The Default Answer (and When to Break It)
Ship a web app first. This is the right answer for the majority of startups. Web apps deploy instantly, require no App Store review (which can take days and come with rejection risk), are easier to iterate on, and are accessible from any device without a download.
But the majority is not everyone. Here are the conditions under which mobile-first makes sense, and the honest accounting of what it costs.
Why Web First Wins for Most Startups
Speed to market
A web app from sign-up to production is days to weeks. An iOS app from development to App Store approval to first download is weeks to months. Google Play is faster than App Store review, but both add friction.
Iteration speed
Fixing a bug in a web app means deploying a new build. Fixing a bug in a native mobile app means releasing a new app version and waiting for users to update. Web development iteration cycles are 5–10× faster.
Cost
Building an iOS app requires Swift expertise (or React Native / Flutter, each with their own learning curve). A native iOS + Android app costs roughly 2–3× more than an equivalent web app. For budget-constrained startups, this is not a trivial difference.
Analytics and experimentation
Web apps are easier to instrument and easier to A/B test. Client-side analytics on mobile require separate SDKs, and App Store rules limit certain forms of experimentation.
When Mobile-First Makes Sense
Your core use case is camera or location dependent
If the app's primary value comes from the camera (photo/video, AR, document scanning) or precise location (delivery tracking, geo-fenced experiences), native mobile is worth the investment. Web camera and GPS APIs have improved but are still limited.
Your users are mobile-only
If your target user does not regularly use a computer (think gig economy workers, consumers in mobile-first markets), building web first means building something your users won't use.
The network effect requires installation
Some apps need to be on the device to work (push notifications, offline mode, home screen presence). If these are core to your retention model and not achievable via PWA, native mobile is the right call.
Distribution is via the App Store
If your go-to-market includes featuring on the App Store / Google Play, or if your users discover apps primarily through app store search, building a web app forgoes that distribution channel.
The Progressive Web App (PWA) Middle Ground
A PWA is a web app that behaves like a native app. It can be added to the home screen, receive push notifications (on supported platforms), and work offline. For many use cases (particularly B2B tools), PWAs eliminate the need for native mobile apps entirely.
PWAs work well for: productivity tools, dashboards, simple workflows. They don't work well for: high-performance graphics, hardware access, App Store distribution.
FAQ
Q: Can I submit a React Native app as both iOS and Android?
Yes. React Native and Flutter are cross-platform frameworks that produce native apps for both iOS and Android from a single codebase. This reduces the cost premium compared to two fully separate native codebases.
Q: Does App Store approval always take a long time?
Apple's review typically takes 1–3 days for new apps and updates, though rejections can extend this significantly. Google Play is usually 1–2 days.
Q: Should I build a mobile app even if I'm starting with web?
Start mobile planning early even if you build web first. Design your API to be mobile-compatible from day one. This makes the eventual mobile app much faster to build.
Q: What's the minimum viable web app that qualifies for mobile?
Responsive design (works on mobile browsers) + a few key mobile UX patterns (bottom navigation, large touch targets, no hover states required). A well-designed responsive web app can serve mobile users adequately until native mobile is prioritised.