Golden Gate Bridge and San Francisco Bay, home of Appther's Bay Area app clients

Mobile App Development Company in San Francisco

Appther is a mobile app development company in San Francisco that builds custom iOS, Android and AI-powered apps for venture-backed startups and the enterprises that buy from them. Senior engineers, Pacific Time hours, a fixed price before the first sprint, and none of the Bay Area agency overhead.

Talk to Our San Francisco Team

Companies that ship with Appther

Axis Bank Xebia Amity University StatusNeo Setia Haruman Joyscore

San Francisco judges an app by its second week, not its launch. Our app developers in San Francisco build for a founder who has to show retention at the next board meeting, an enterprise buyer who will not sign without a SOC 2 report, a clinician on a Mission Bay campus, and a user who will churn the moment onboarding asks one question too many.

What Our San Francisco App Developers Deliver

Native Swift and Kotlin apps, or a single Flutter or React Native codebase that ships to both stores

Investor-ready MVPs in 8 to 14 weeks, instrumented so the retention chart is real before the next raise

Backends and APIs on AWS and Google Cloud, designed to grow from a pilot to a Series B without a rewrite

SOC 2 readiness, CCPA and CPRA, CMIA and PCI DSS handled in the architecture before an enterprise buyer asks

Integration with Stripe, Plaid, Salesforce, HubSpot, EHRs and the SaaS platforms your customers already use

Research, design systems and App Store and Google Play release management

200+Apps and platforms delivered worldwide
50+US clients served since 2018
10+Industries served, from fintech to food
100%Job success score on Upwork

iOS, Android and Cross-Platform App Development Services in San Francisco

From a SoMa startup racing to a seed-stage demo to a Peninsula enterprise adding a mobile companion to its SaaS platform, our app developers in San Francisco cover the whole stack. Choose the service that fits, or describe the problem and we will tell you which platform earns its place.

iOS App Development

iOS app development in San Francisco for products whose first users own the newest iPhone and expect it to show: Swift and SwiftUI, Core ML for on-device intelligence, HealthKit and Combine where the product calls for them, shipped through Fastlane and TestFlight with the release notes your investors will actually read.

  • Plugged into the Bay Area stack: Stripe, Plaid, Salesforce, HubSpot, Segment and your own APIs, so the iPhone app is a product surface rather than a demo.
  • Instrumented for the board deck: activation, retention and revenue events wired in from the first build, with crash and performance monitoring alongside.

Android App Development

Android app development in San Francisco with Kotlin and Jetpack Compose, because the users who will actually pay for a marketplace, a field tool or a health app are on Android as often as not. We handle Play Console policy, Play Integrity and background-work limits so the first review is not a rejection.

  • Beyond the Peninsula: tested on the mid-range devices your users in Oakland, Fresno and Manila carry, not just on a flagship in Palo Alto.
  • Built to be sold to enterprises: managed Google Play distribution, MDM compatibility and offline-first sync for the workforce apps enterprise buyers ask for.

Flutter App Development

One Dart codebase for iOS, Android and web, rendered at 60 frames per second with pixel-level control. Our Flutter developers reach for it when a San Francisco startup needs both stores on a seed budget and a single launch date.

  • Runway-friendly: one team and one backlog for both platforms, which is how a funded idea reaches both stores in weeks instead of quarters.
  • Native when it counts: platform channels for biometrics, payments, Bluetooth and camera work, so shared code never blocks a feature a competitor already has.

React Native App Development

For teams already shipping a React web app, React Native is the shortest path to mobile: shared logic, shared components and engineers who move between surfaces. We build on the new architecture with Hermes, use Expo where it speeds you up, and write native modules where it does not.

  • Your web team, extended: API clients, design tokens and business rules reused across the web app and both stores.
  • Iterate at startup speed: over-the-air updates for content and logic, with a rollback if a release misbehaves, so a Tuesday fix does not wait for Thursday's review.

MVP Development

A minimum viable product that is actually viable: one core loop, built to measure, shipped to both stores in 8 to 14 weeks. We scope it with you down to the feature that proves the thesis, and we leave the rest for the version your users ask for. See our mobile app development practice for the full range.

  • Built to learn: analytics, feature flags and an experiment framework from day one, so the retention number in your next deck is real.
  • Built to grow: an architecture that survives the jump from a pilot to a Series B without a rewrite, because we have watched what happens when it does not.

Web App Development

Admin consoles, customer dashboards and partner portals, built in React and Next.js against the same backend as the app, so custom software development in San Francisco gives you one product with several surfaces rather than three products with three backlogs.

  • One backend, every surface: shared APIs, permissions and audit logs behind web, iOS and Android.
  • Accessible by design: WCAG 2.2 AA from the first component, which matters both to enterprise procurement and under California's Unruh Act.

Progressive Web Apps

For products that should not wait on a store review: internal tools, B2B ordering, event apps and early prototypes you want in users' hands this week. Our hybrid and PWA builds install from a link, work offline through service workers, and push where the browser allows.

  • Ship today: no review queue, and the install is a URL you can paste into a Slack channel.
  • Offline where it matters: forms and workflows that keep running in a BART tunnel or a warehouse dead zone, then sync when the signal returns.

AI-Powered App Development

AI-native products and AI features inside existing ones: assistants, recommendations, document understanding and computer vision. Our AI development practice brings LLM features and predictive models into mobile apps with the evaluation, cost controls and disclosures a Bay Area buyer will ask about.

  • Grounded and evaluated: assistants that answer from your own data with sources attached, tested against an evaluation set before every release.
  • Private and disclosed: models deployed in your own cloud tenancy, no training on customer data without consent, and California bot disclosure built into the interface.

Building an App in the Bay Area?

Whether it is the product your seed round was raised for, the mobile companion your enterprise customers keep asking about, or a health app that has to clear a clinical review, an app built in San Francisco is judged on its numbers. Send us the idea and we will return a platform recommendation and a scoped plan.

Start With a Free Scoping Call
Founder reviewing a mobile app on a phone beside a laptop

Apps We Have Shipped, and the Numbers They Moved

Six products from our portfolio that map to what the Bay Area builds: consumer health, fintech, AI agents, support automation, education and mobility. Metrics come straight from the published case studies.

01 / 06Consumer healthiOS · Android

DeepRest: a consumer wellness app built to deliver relief in the first ten seconds

The problem

Wellness apps lost anxious users in long onboarding flows and sprawling meditation libraries, right at the moment those users needed something simple.

What we built

A mobile-first, HIPAA-ready app with guided breathing, 21-day anxiety reset programs and panic relief that starts from the first tap, instrumented to prove it.

95%of users felt calmer with regular use
21-daystructured programs
2stores, live on day one
Read the case study
DeepRest anxiety and sleep relief app screensDeepRest · Consumer health

What Clients Say About Working With Appther

"Implementing an ERP across our sugar manufacturing operations felt daunting at first, but Appther made the transition seamless. From production planning to inventory and supply chain visibility, every department now works off a single source of truth."

Pushpender KumarPushpender KumarGeneral Manager, AB Sugar Ltd

Industry-Specific App Development for the Bay Area's Core Sectors

Software, fintech, biotech and healthcare, marketplaces and the AI companies now filling SoMa: the Bay Area builds products for the rest of the world, and it buys them with a procurement checklist. Our mobile app development company in San Francisco shapes each product around that sector's workflow, buyer and regulator.

California and US Compliance Built Into Every App We Develop

In San Francisco the compliance question arrives from two directions at once: the state, with the strictest consumer-privacy regime in the country and new rules for AI, and the enterprise buyer, who wants a SOC 2 report before the pilot. We design for both with your counsel before the first screen.

Encrypted data platform illustration for privacy-compliant mobile apps Engineers preparing SOC 2 evidence for an enterprise buyer Card payment being entered on a laptop, representing PCI DSS-compliant checkout Engineer verifying secure mobile app access on a phone and laptop Accessible mobile app interface designs on a phone

Privacy & Consumer Rights

  • CCPA and CPRA: access, deletion and correction flows, Global Privacy Control honored, and risk assessments where the app makes automated decisions
  • Confidentiality of Medical Information Act (CMIA) alongside HIPAA for any product touching health data
  • CalOPPA privacy-policy requirements and the Delete Act for anything that shares data with brokers
  • COPPA and age-appropriate design requirements where a product reaches younger users
  • GDPR and other US state privacy laws for users beyond California

Enterprise Buyer Requirements

  • SOC 2 Type II control readiness: access reviews, change management, logging and vendor management built into how the app is run
  • Security questionnaires, penetration-test reports and architecture documents prepared for the procurement cycle
  • Single sign-on with Okta, Google Workspace and Microsoft Entra, plus SCIM provisioning where buyers require it
  • Data-processing agreements and sub-processor lists you can hand to a customer's legal team
  • Tenant isolation, data residency and retention controls that hold up in an enterprise review

Payments & Subscriptions

  • PCI DSS 4.0 scope kept small by tokenizing cards with Stripe, Braintree or your processor at the point of entry
  • California's Automatic Renewal Law: clear disclosure, affirmative consent and one-click cancellation for subscriptions
  • Apple and Google in-app purchase rules, and when a web checkout is allowed instead
  • Plaid, KYC and fraud-screening integrations for fintech onboarding
  • Strong customer authentication with Apple Pay, Google Pay and 3-D Secure

Application & AI Security

  • OWASP Mobile Application Security Verification Standard (MASVS) applied to every release
  • Prompt-injection, data-leakage and abuse testing for LLM features, with evaluation sets run before each deploy
  • NIST Cybersecurity Framework alignment for identity, detection and response
  • Encryption at rest and in transit, certificate pinning and hardware-backed key storage on device
  • Independent penetration testing before major releases, with findings fixed rather than filed

Accessibility, AI Disclosure & Store Policy

  • ADA Title III and California's Unruh Civil Rights Act, met through WCAG 2.2 AA and tested with VoiceOver and TalkBack
  • California bot-disclosure and AI transparency requirements for assistants and generated content
  • App Store Review Guidelines and Google Play policies, including account deletion and data-safety disclosures
  • TCPA consent for SMS, push-to-text and automated calls
  • Section 508 for public-sector and grant-funded work

Why San Francisco Companies Hire Appther as Their App Development Partner

A mobile app development company in San Francisco competes with the best product teams in the world for the same users. Five reasons founders and product leaders keep us on past the MVP.

01

Senior engineers without the Bay Area agency bill

The people who scope your app are the people who build it: senior engineers who have shipped wallets, clinical apps and marketplaces, at a fixed price that leaves runway for the marketing you will need after launch.

02

MVPs that are actually minimum and actually viable

We scope down to the loop that proves the thesis, instrument it to measure activation and retention, and build it so the next version is an iteration rather than a rewrite.

03

Enterprise-ready before the first enterprise asks

SOC 2 controls, SSO, tenant isolation and a security questionnaire that is already answered, because the pilot with the Fortune 500 logo should not stall on paperwork.

04

A price that holds, a scope in writing, one engineer on the hook

Discovery ends with a fixed quote and a signed scope. A named senior engineer on Pacific Time runs the build, demos every two weeks, and there is no timesheet surprise at month end.

05

Reported on the metric in your deck

Activation, week-four retention, revenue per user, tickets deflected. We agree the number in discovery, wire the analytics to it, and tell you plainly when a requested feature will not move it.

Add AI to Your Product Without Turning It Into a Research Project

Assistants, recommendations and document understanding scoped to one outcome, evaluated before release and shipped inside the product you already have. San Francisco teams use us for:

In-app assistants grounded in your own data, with sources attached
Document, ID and image understanding that speeds up onboarding
Recommendations and forecasts that lift retention and revenue
Scope an AI Feature
Businessperson holding an AI hologram, representing AI-powered mobile apps

Four Reasons Apps Stall in San Francisco, and How We Clear Them

Bay Area projects rarely fail on features. They stall on an MVP that never becomes a product, an enterprise pilot blocked by a security questionnaire, an architecture that cannot survive its own growth, and a retention curve nobody instrumented.

0104
Challenge 01 of 04

MVPs that never become products

What goes wrong

The prototype demoed well and raised the round, but it was built on shortcuts that make every new feature slower and every new engineer more expensive.

How we clear it

We build the MVP on the architecture the product will need at Series B: clean domain boundaries, real authentication, feature flags and tests, so version two is an iteration rather than a rewrite.

Scalable product architecture illustrationArchitecture
Challenge 02 of 04

Enterprise pilots blocked by a security questionnaire

What goes wrong

The buyer loves the product, then procurement sends a 200-question assessment and asks for a SOC 2 report, and the pilot slips two quarters.

How we clear it

We design to the questionnaire from the start: SSO, access reviews, logging, encryption, vendor management and documentation that already exists when the buyer asks.

Developers reviewing security controls for an enterprise pilotEnterprise readiness
Challenge 03 of 04

Growth the architecture cannot survive

What goes wrong

A launch on a popular newsletter or a feature on the App Store sends ten times the traffic, the database locks up and the reviews turn in an afternoon.

How we clear it

Stateless services, queues, caching and autoscaling, load-tested against the launch you are hoping for rather than the traffic you have today.

Engineering team planning for scaleScale
Challenge 04 of 04

Retention nobody instrumented

What goes wrong

Installs look great, but nobody can say which onboarding step loses users, which notification brings them back or what week-four retention actually is.

How we clear it

Analytics, funnels and experiment tooling wired in from the first build, with onboarding and notifications designed around one retention number and tuned on live data.

Mobile app onboarding and engagement screensRetention

Emerging Technologies We Bring Into San Francisco App Projects

In a city where every deck mentions AI, we add these only where they move a metric for the user or the business. Each card links to the practice that builds it.

Artificial Intelligence (AI)

Ranking, personalization, fraud and forecasting models trained on your own data, with an evaluation set and a cost ceiling agreed before the first deploy.

Generative AI

In-app assistants and copilots that answer from your documents and data with sources attached, tested for prompt injection and hallucination before each release.

AI Agents

Agents that complete multi-step tasks across your own APIs, with human approval on anything that spends money or touches a customer record.

Data Analytics

Product, revenue and support data turned into dashboards a founder can read the morning of the board meeting, not after the analyst finishes the export.

AI Voice Agents

Voice agents that answer patient and customer calls around the clock, book and reschedule, and hand off to a human with the transcript attached.

Blockchain & Web3

Wallet integrations, tokenized assets and on-chain records for products where ownership or provenance has to be provable, built so mainstream users never see a seed phrase.

Our Mobile App Development Tech Stack

Deliberately unexciting. Each tool below has passed an enterprise security review, has a deep talent pool in the Bay Area, and will still be maintained when your app is five years old.

Swift SwiftUI & UIKit Xcode iOS SDK Kotlin Jetpack Compose Android Studio Android SDK
Flutter Dart React Native Expo Ionic
Node.js NestJS Python Django FastAPI Laravel Go
PostgreSQL MongoDB MySQL Redis Firestore SQLite Supabase
AWS Microsoft Azure Google Cloud Docker Kubernetes Terraform
Auth0 Okta Keycloak Firebase Auth Face ID & Biometrics OAuth 2.0 / OIDC
Firebase Cloud Messaging Apple Push Notification service OneSignal Twilio SMS & WhatsApp
Stripe Braintree PayPal Square Apple Pay Google Pay Plaid & ACH
Google Analytics 4 Mixpanel Sentry Datadog Grafana Crashlytics
GitHub Actions GitLab CI Fastlane Bitrise Jenkins TestFlight

How much will your app cost to build in San Francisco?

Send us the idea and we will return a scoped estimate with the platform, team and timeline behind the number, usually within one business day, at a fraction of Bay Area agency rates.

Get a Scoped Estimate
Mobile app screens and code used to scope an app development estimate

How We Build Mobile Apps for San Francisco Clients

Six stages, each ending in something you can open, click or sign. Instrumented from the first build, fixed-price from the first sprint.

01

Discovery and scope

We start with the thesis the app has to prove and the metric that proves it, then map the compliance surface: CCPA and CPRA for data, CMIA for health, SOC 2 for the enterprise buyer, subscription rules for revenue. You leave with a written scope and a fixed price.

02

Fixed-price plan

Timeline, team, integrations and release plan agreed in writing, sequenced against your fundraising and sales calendar so the demo exists before the meeting that needs it.

03

UX research and UI design

Our app developers in San Francisco design for the person actually holding the phone: a first-time user on a crowded App Store page, a clinician between patients, an enterprise admin setting up SSO. Wireframes, clickable prototypes and a design system are tested with real users before production code.

04

Sprint-based development

Two-week sprints that each end with a build on your phone. Native Swift and Kotlin where the product needs it, Flutter or React Native where one codebase is the smarter spend, with the backend and integrations built alongside so nothing idles.

05

QA, security and accessibility testing

Real devices, throttled networks and offline mode, plus security testing against OWASP MASVS, LLM abuse testing where there is AI, and accessibility checks against WCAG 2.2 and the Unruh Act. Nothing ships with an open critical.

06

Store launch and growth

App Store and Google Play submission, release monitoring and the first weeks of hypercare, then an SLA-backed support plan with activation, retention and performance dashboards you can paste into a board deck.

Appther across the US

USA hub New York, NY Los Angeles, CA Chicago, IL Houston, TX Dallas, TX Austin, TX Miami, FL Seattle, WA Boston, MA Atlanta, GA Charlotte, NC (AI)

San Francisco App Development FAQs

Mobile app development cost in San Francisco depends on scope, platform, design complexity, the backend and integrations behind the app, and advanced features such as AI, payments or biometrics. Our senior engineers work at a fixed price that is well below Bay Area agency rates for the same seniority, and every line item is visible in the quote.

  • Focused MVPs typically run $15K to $40K
  • Mid-scale products with a custom backend and integrations run $40K to $80K
  • Enterprise and AI-native platforms with compliance and multi-system integration start at $80K+

Want a real number? Talk to our team for a fixed-price quote on your San Francisco app, with no open-ended billing after discovery.

A focused MVP reaches both stores in 8 to 14 weeks from kickoff. That assumes one core loop, a real backend and analytics from day one, and a founder who can make decisions inside a sprint. Products with a custom backend and several integrations run 3 to 6 months; enterprise and AI-native platforms with security reviews and multiple roles usually pass 6 months. You get a build on your phone every two weeks either way.

No, and we do not pretend to be. Appther's US entity is registered in Southern California, and delivery runs remote-first with the US-facing team on Pacific Time, so stand-ups, demos and escalations happen inside your working day. A named senior engineer is your single point of contact from kickoff to launch, which is more than most Bay Area agencies offer once the contract is signed.

Yes. We build the app and its infrastructure to SOC 2 Type II controls from the start: SSO and SCIM, role-based access with periodic reviews, change management, centralized logging, encryption, vendor management and the documentation an auditor and a buyer's procurement team will ask for. The audit itself is run by your chosen firm; our job is to make sure the evidence already exists when they arrive.

Yes. Most consumer, marketplace and B2B companion apps start on Flutter or React Native so one codebase reaches both stores on one budget. Products built around hardware, heavy graphics, background processing or platform-specific features go native in Swift or Kotlin. We make the call in discovery and write the reasoning into the scope, so the choice is deliberate rather than a habit.

Compliance is mapped with your counsel in discovery and then designed in. For CCPA and CPRA that means access, deletion and correction flows, honoring Global Privacy Control, a documented map of every third-party data flow and risk assessments where the app makes automated decisions. For AI features we build in bot disclosure and the transparency California now requires for generated content, and we do not train on customer data without consent. For health data we design to CMIA, which is stricter than HIPAA. The controls are documented as they are built, so a regulator or an auditor can follow them.

You do, and it matters for your next round: investors will ask. Repositories live under your organization, store accounts are opened in your company's name, infrastructure runs in a cloud account you control, and intellectual property is assigned to you as each invoice is paid. An NDA is signed before discovery, and if you ever bring the work in-house the handover is a matter of revoking our access.

The first weeks are hypercare: crash rates, latency, store reviews and the activation funnel are watched daily and fixed as issues surface. From there you choose a support tier with a written SLA, OS-update coverage, security patching and a monthly report on retention, revenue and performance, plus a scaling review before any launch you expect to trend.

Mobile App Development Guides From Our Blog

Business-plan templates, cost breakdowns and AI architecture notes we send Bay Area founders before the first call, so the conversation starts from real numbers.

Mobile App Business Plan & Examples for Startups
Blog · Startups

Mobile App Business Plan and Examples for Startups

Read the article
How Much Does It Cost to Build a Mobile App in 2026? A Realistic Breakdown
Blog · Pricing

How Much Does It Cost to Build a Mobile App in 2026? A Realistic Breakdown

Read the article
How to Implement RAG in Your AI System: Architecture, Process, and Cost Breakdown (2026)
Blog · AI

How to Implement RAG in Your AI System: Architecture, Process and Cost

Read the article
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Let's Build Your San Francisco App

Tell us what the app has to prove and who it is for. An engineer replies with an honest take on approach, scope, timeline and cost, and nobody follows up with a sales sequence. Prefer email? Use our contact page.

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