We design and build mobile and web products end to end — discovery, design, engineering, launch and the boring parts that decide whether it survives contact with real users. You get the source, the infrastructure and the documentation, and a team that stays only if you want one.
Exelero builds mobile and web applications for clients: native iOS and Android, cross-platform apps in React Native and Flutter, and web applications and platforms. Work covers product discovery, UX and UI design, engineering, QA, app store release and post-launch support.
Clients receive the source code, infrastructure and documentation on handover, with ongoing maintenance available but never required. Engagements run as fixed-scope builds, as MVP builds for new products, or as a dedicated team working alongside an in-house one.
The demo always works. What decides whether a product survives is the rest: what happens when the network drops mid-transaction, when the token expires, when a user has 40,000 records instead of 40, when the App Store changes a rule, when the person who understood the codebase leaves. Most of the cost of software is incurred after launch, and most of it is determined before launch by decisions nobody documented.
We build for the handover from day one, because that’s the honest test of an agency’s work — not whether it launched, but whether your team could take it over next month without calling us.
Native iOS in Swift and Android in Kotlin; cross-platform in React Native and Flutter; offline-first architecture and sync; push notifications; in-app purchases and subscriptions; biometric authentication; camera, location, Bluetooth and hardware integration; accessibility; App Store and Play Store submission and review handling.
Web applications and platforms in React, Next.js, Vue and TypeScript; design systems and component libraries; real-time features; complex dashboards and admin tooling; progressive web apps; internationalization including right-to-left.
API design in REST and GraphQL; Node, Python and Go services; PostgreSQL and other data stores; authentication and authorization; third-party integrations; cloud infrastructure as code; CI/CD; observability and alerting.
Product discovery and scoping; user flows and wireframes; UI design and prototyping; design systems; usability testing; accessibility review.
Automated test coverage, manual QA across devices, performance profiling, security review, and a release process your team can run without us.
We build in 8–12 weeks from scope to launch, starting from foundations already built rather than an empty repository, with scope fixed in the first two weeks and one team across the whole stack. A focused MVP lands inside the range. A full product with backend, admin tooling and several integrations runs longer, and we say so during scoping rather than discovering it in month four.
One to three weeks. Scope, user flows, architecture and a build plan with a real number attached. You own the output whether or not we build it.
Defined scope, defined timeline, defined price. Weekly demos, staging from early on, no surprises at the end.
For new products: the smallest version that tests the actual assumption, built to be extended rather than thrown away.
Our engineers inside your process, for teams that need capacity.
Source, infrastructure, documentation and a walkthrough. Support on a retainer if you want it.
Founders building a first product who need a team that can also tell them what not to build. Companies digitizing an operation currently running on spreadsheets and phone calls. Businesses with an ageing app that needs rebuilding rather than patching. In-house teams who need extra capacity for a quarter without hiring for it. Enterprises who need something built outside the internal roadmap queue.
8–12 weeks from scope to launch for a focused product. Discovery gives you a firm date in week two rather than an optimistic one on day one.
It depends almost entirely on scope, and any agency quoting before understanding yours is guessing. A focused MVP is a different project from a platform with payments, real-time sync and an admin back office. Our discovery phase ends with a fixed scope and a fixed price, and you keep that output even if you build elsewhere.
Yes. Source, infrastructure and documentation transfer to you on handover. No licence, no lock-in.
Cross-platform when the product is mostly screens, data and forms, which is most products. Native when performance, deep hardware access or platform-specific behaviour matters. We’ll tell you which yours is and why, rather than defaulting to whichever we prefer.
Yes. We start with an audit and an honest assessment of whether it’s worth continuing or rebuilding — including when the answer is that it’s fine and you don’t need us.
No. That’s a shorter, cheaper engagement: four weeks, fixed scope, fixed price. See Website Development. This page is for products with users, accounts and business logic behind them.
Yes, and we prefer to. Handed a finished design we’ll build it, but the best results come from design and engineering scoping the thing together.
Bring a spec, a sketch or a problem. We’ll come back with scope, timeline and price.