iOS and Android App Development
Mobile apps designed around your end user, built for performance and solid UX from the very first screen.
We build apps for iOS and Android using whichever technology fits the project — native when performance and device-level access are critical, or cross-platform when the goal is speed and reach on both systems from a single codebase.
The process starts by understanding the user flow: which screens actually matter, what needs to feel instant, and what can stay simple. From there we design the interface, build the app in short delivery cycles, and test on real devices before any release.
We also handle store publishing — App Store and Google Play — including developer account setup and the review process, so the app reaches your end user without friction.
What's included
- UI design and user experience (UX)
- Native (Swift/Kotlin) or cross-platform development
- Integration with APIs, backend, and third-party services
- Testing on real iOS and Android devices
- Publishing on the App Store and Google Play
- Support and iteration after launch
Benefits
- An app designed for your actual users, not a generic template
- Technology chosen to fit your budget and timeline
- Direct communication with the people building it
- Code organized to take on new features down the line
- Guidance through the entire store submission process
Related work
Our own app for iPhone and iPad
Hotaru
A flashcard app built and published by JJ Software. It turns notes, photos and PDFs into cards with Apple Intelligence, on device, and schedules reviews with FSRS, the spaced repetition algorithm behind Anki.
Our own app for iPhone, iPad and Apple Watch
Everyish
A habit tracker designed with ADHD brains in mind, built and published by JJ Software. Instead of resetting your streak at the first slip, it uses grace days, guided routines and a dopamine menu to help you come back.
Our own app for iPhone and iPad
Cobrei
An app for Brazilian micro-entrepreneurs (MEI) and freelancers, built and published by JJ Software. It tracks hours per client, turns them into PDF invoices and receipts with a Pix QR code, writes a ready-to-send payment reminder for WhatsApp, and keeps the MEI revenue limit and monthly tax in view.
Questions about this service
Do you build for iOS and Android at the same time?
Yes. Depending on the project, we build natively for each platform or use a cross-platform codebase, which usually reduces cost and timeline without sacrificing quality.
Do I need an Apple and Google developer account?
Yes, the developer account belongs to the client — that way the app and its data stay under your ownership. We help with the entire account setup process.
How long does it take to build an app?
It depends on complexity. Simpler apps usually take 6 to 10 weeks; more robust projects can take a few months. We set a realistic timeline once we understand the scope.
Got a project in mind?
Tell us what you need to build and we'll get back to you with a straightforward proposal.