Each frame below is a feature. Circle the ones your first version needs and the estimate develops as you go: a price range, a timeline and what drives both. No email needed, and the link keeps your answers.
Unpicked frames stay as negatives. Days are for one platform, before design and stage.
An app's price is mostly time: the days of design, engineering and testing it takes to put a first version in front of real users. Four things move that number more than anything else.
Each platform is somewhere your app has to work, be tested and be released. iOS and Android built from one shared codebase cost less than two separate native apps, but more than one. A web app alongside them adds its own screens and its own testing.
If money is tight, launching on the platform most of your users already carry, and adding the second once people are using it, is the most common saving.
Features are where most of the days go, and they are not equal. Sign-in is a few days. Chat, payments, offline sync or anything with machine learning takes weeks, because each one brings a backend, edge cases and new ways to fail in the real world.
Every feature also needs testing, a way to manage it and support after launch. The cheapest feature is the one you postpone until users ask for it.
A clean interface built from proven components is quick. A custom look takes more design rounds, and signature motion (animated transitions, gestures, illustration) adds design and front-end time to every screen.
Good design isn't optional. How custom it is, is a choice you can make screen by screen.
Starting from an idea means the first days go on deciding what to build: who it's for, the main flows and the risky parts. Arriving with tested designs or a prototype shortens that.
Improving a live product skips the blank page, but adds time to read the existing code, work around real users and release without breaking anything.
Hosting and cloud bills, Apple and Google developer accounts, paid services such as maps, AI models, SMS and payment processing, content, and maintenance after launch. They are usually small next to the build, but they recur, so plan for them.