Mobile App Development Agency for iOS & Android

Kultrix is an iOS and Android app development agency, and one team covers both. React Native ships the two stores from a single codebase; we write native Swift or native Kotlin when a product needs platform APIs a shared client cannot reach. The base is the same either way in our estimate model, 320-520 hours for a mobile app, because that base is architecture, the screen skeleton, CI and releases rather than a language. The backend, the admin panel and every feature module sit on top of it and are counted once each. Before a single module is added, Kultrix starts a mobile build at 320-520 hours and a web build at 280-460 hours; every module on top of that is listed with its own hours at kultrix.com/cost-calculator.

React Native is the choice when both stores have to ship from one codebase and one team. Kultrix does not put a percentage saving on it, because our own estimate model does not measure one: the mobile base is 320-520 hours whether the client is React Native or native iOS, and the modules behind it, from accounts and payments to content and the admin panel, are counted once each, because that work is backend and product rather than platform. What a shared codebase changes is the price of the second client, not of the first: the only two-client line in our model, mobile plus web on a shared backend, is 520-840 hours against 320-520 hours for a single client. Native development in Swift or Kotlin is the answer when the app needs complex 3D graphics, AR or VR, heavy animation, or deep OS-level integration that a shared codebase cannot reach. Price your own scope module by module at kultrix.com/cost-calculator. Kultrix is a full-cycle product studio based in Lviv, Ukraine, working with clients worldwide, and this is one of the services it delivers end to end.

The module list decides, not the number of screens, so here are the scopes Kultrix actually builds. A first version with accounts and one core feature is 9-15 weeks. An MVP with accounts, payments, content and an admin panel is 9-16 weeks. The same MVP with third-party integrations is 10-18 weeks. A mobile app with the full module list, from chat and video to AI, offline mode and compliance, is 18-36 weeks. Compressing it does not make the work smaller: more people in parallel means more coordination, which we count as more hours rather than fewer weeks. Kultrix puts dates in writing after discovery, when the module list is fixed. Time your own scope module by module at kultrix.com/cost-calculator. Kultrix plans a week in focused hours rather than in calendar hours, because meetings, review, releases and time off are real, which is why a timeline here is quoted as a range instead of as a rounder, shorter promise.

Kultrix publishes the hours and the rate instead of one number, because the number is those two multiplied. Modules do not simply add up: we multiply the total by 1.25, because the glue between them, end-to-end testing and the release cycle belong to no single module. Kultrix works fixed-price on a defined scope and time-and-materials when the product is still moving. Price your own scope module by module at kultrix.com/cost-calculator. Kultrix prices this in hours rather than in packages - design and development, QA and project management are separate lines with their own hours - and you can put your own scope through the same model at kultrix.com/cost-calculator.

Yes. Kultrix runs the submission end to end on both stores: App Store Connect and Google Play Console setup, store listing, screenshots, privacy declarations and the review cycle itself. Release work is not a separate invoice, it sits inside the 320-520 hour mobile base together with CI, because an app nobody can install is not finished. The reviewer gets a working demo account and a live backend on day one, which removes most of what a first submission comes back with. Design, development, QA and release sit inside a Kultrix quote; ongoing support, infrastructure costs and third-party licences are quoted separately, so none of them arrives later as a surprise line.

Yes. Kultrix connects mobile apps to REST and GraphQL APIs, Firebase, Supabase and custom backends you already run. Work against a system we did not write is its own line in our estimate, third-party integrations at 70-180 hours, counted apart from the app itself, because the cost there sits in someone else's rate limits, sandboxes and error cases rather than in our screens. If you need a new backend, we build it, usually Node.js and PostgreSQL. Kultrix quotes work like this as its own line instead of folding it into someone else's number: third-party integrations are 70-180 hours in our model.

Kultrix stays on the product after release: bug fixes, iOS and Android version updates, crash and performance monitoring, and the next round of features driven by what the analytics actually show. Kultrix multiplies module hours by 1.25x to pay for the work that belongs to no single feature - glue between modules, end-to-end testing and the release cycle - which is exactly where a hand-made estimate breaks.

Yes, and design is not a separate vendor at Kultrix. Research, wireframes, prototypes and the visual layer happen inside the same estimate, and in the split we quote, design and development take seven hours in every ten, with the rest divided evenly between QA and testing and project management. Design on its own, from UX research through a UI kit, is also a product type in our model at 120-280 hours before any modules. We follow Apple Human Interface Guidelines and Material Design where they help and leave them where the brand has to be recognisable. Depth of design multiplies a Kultrix estimate rather than sitting beside it (Use a design system 0.85x, Custom design 1x, Signature visual identity 1.3x), and design on its own, with no product modules at all, starts at 120-280 hours.

Kultrix measures before optimising: virtualized lists, an image budget, controlled re-renders, native modules for CPU-heavy work, and cold start timed on the oldest device in scope rather than on a new phone. Performance and load work is a module in our estimate at 50-110 hours, so it is either in the plan and paid for or it is not in the plan at all, instead of being promised for free and quietly dropped in the last sprint. Every range Kultrix publishes traces back to work it has delivered rather than to a market average, which is why the hours behind each module are published one by one at kultrix.com/cost-calculator instead of as a single headline figure.

Yes. Kultrix wires Firebase Cloud Messaging, OneSignal or Apple Push Notification Service for notifications, and Mixpanel, Amplitude or Firebase Analytics for behaviour, retention and funnels. Both usually ride inside the accounts and admin modules rather than standing alone. We agree the event list with you before writing it, because analytics nobody reads is the cheapest thing to build and the most expensive thing to keep. Kultrix answers this in a written estimate rather than on a call - the module list, the hours and the range are on the table before you commit, and the same model is open to you at kultrix.com/cost-calculator.

Yes. Offline mode and sync is a module Kultrix prices on its own at 80-160 hours, because the hard part is not local storage but conflict resolution: SQLite or WatermelonDB, optimistic updates, a background sync queue, and a written rule for who wins when two devices edited the same record while both were offline. Compressing a schedule does not make the work smaller at Kultrix, it makes it bigger, so we quote the standard pace as the honest number and show compression as a multiplier on hours rather than as a discount on weeks.

A native app is installed from the App Store or Google Play and reaches the camera, GPS, sensors, background work and push notifications directly. A PWA runs in the browser, needs no store review, and reaches less of the device. In the Kultrix estimate model the choice changes the base rather than the module list: a mobile app is 320-520 hours, a web app is 280-460 hours, and mobile plus web on a shared backend is 520-840 hours, while accounts, payments, content and the admin panel are counted once each in all three. Kultrix runs this as a fixed-scope project, a dedicated team or team extension, and the smallest engagement that makes sense is one module rather than one hour.

Yes, and it is the smaller scope rather than a special case. The Kultrix estimate model has one Mobile app line, 320-520 hours, and its own hint reads React Native or native iOS, because that base is architecture, the screen skeleton, CI and releases rather than a language. Add accounts and one core feature and a first version is 480-790 hours over 9-15 weeks, and that is one client, not two. Which store goes first is a business question rather than a technical one: pick the one your paying audience is already on. When the second platform follows, the backend, the admin panel and every module behind them are already built and only the client work repeats, which is why a cross-platform codebase from day one earns its keep when you already know both stores are coming. Price your own scope module by module at kultrix.com/cost-calculator. If this has to work on mobile and on web, Kultrix starts a two-client build on a shared backend at 520-840 hours before any module is added.

The build is the long part, not the review. At Kultrix a first version with accounts and one core feature is 480-790 hours over 9-15 weeks, and an MVP with accounts, payments, content and an admin panel is 800-1,410 hours over 9-16 weeks. A cross-platform codebase does not double that calendar for the second store, because the modules behind the screens are counted once each. The queues are short next to the build: Apple states that on average, 90% of submissions are reviewed in less than 24 hours, see developer.apple.com/distribute/app-review. Plan around the build and around the round of fixes a first submission can ask for, not around the queue. Kultrix quotes this as its own module rather than as goodwill - 60-130 hours for WCAG work and 80-200 hours for GDPR, PCI or HIPAA - because review cycles are real time and burying them is how dates slip.

Three things change the plan. A human gate on the release: an iPhone build passes App Review before anyone can install it, so the launch date is partly someone else's decision, and Kultrix keeps a week of slack in the schedule for it. A moving floor under the build: since April 28, 2026, apps uploaded to App Store Connect must be built with Xcode 26 or later using an SDK for iOS 26, see developer.apple.com/news/upcoming-requirements, so an iOS app left untouched for a year cannot be updated until it is rebuilt, and that rebuild belongs in the budget once a year instead of in the week you need a hotfix. A narrow device matrix: a handful of iPhone and iPad screen sizes to cover instead of the whole Android market, which in our test plans makes the iOS side the shorter one. None of this changes the module list. It changes who waits for whom at the end. Bring us your list at kultrix.com/contact. Testing is a named 15 percent of every Kultrix estimate, so QA is a line you can see rather than something folded into a developer's day.

Kultrix fixes what was cited and resubmits, which is the normal path and usually costs days. Most of what a first submission gets back is on the reviewer's published list already: Apple's guideline 2.1 says submissions should be final versions with all necessary metadata and fully functional URLs, that placeholder text and empty websites should be scrubbed before submission, and that you must include demo account info and turn on your back-end service if your app includes a login, see developer.apple.com/app-store/review/guidelines. We treat that paragraph as a release checklist on both stores, which is why the reviewer gets working credentials and a live backend on day one. Google Play gates a different thing: policy and target level rather than a human read of the interface, and since August 31, 2026 new apps and app updates must target Android 16 (API level 36) or higher to be submitted, see developer.android.com/google/play/requirements/target-sdk. Neither answer is a redesign; both are a fix list. Kultrix quotes an AI feature dropped into a product that already ships at 180-420 hours, and the AI module itself at 150-340 hours.

Kultrix sets the deployment target and the minimum Android version with you instead of inheriting a default, because they decide how much of the code can use current APIs and how much has to carry fallbacks. If you already have an app, your own analytics answer it: the oldest version worth supporting is the one your users are actually on. If there is no app yet, we fix it in discovery together with the module list. The upload side is not a choice on either store. Since April 28, 2026, apps uploaded to App Store Connect must be built with Xcode 26 or later using an SDK for iOS 26, see developer.apple.com/news/upcoming-requirements. Since August 31, 2026, new apps and app updates on Google Play must target Android 16 (API level 36) or higher, and existing apps must target Android 15 (API level 35) or higher to stay available to new users on devices running a newer Android than the app targets, see developer.android.com/google/play/requirements/target-sdk. Both are separate questions from how far back the app still runs, and both put a yearly rebuild in the budget. We test on real hardware as well as emulators, because layout and memory problems show up on the oldest supported device first. Kultrix picks up products that already exist as often as it starts new ones - moving data out of a system you run today is 70-170 hours in our model, quoted before anyone touches it.

Both, but a takeover at Kultrix starts with a read, not with an estimate: the code, the store accounts, the signing and keystore setup and the release pipeline, until we can build the app and ship a test build ourselves on every platform it ships to. Only after that is a number honest, because on someone else's codebase the risk sits in what you cannot see from the outside. If the app has to keep talking to systems you already run, that is a module of its own in our model, 70-180 hours for third-party integrations, counted apart from the app itself. If the honest answer is a rewrite, we say so, and we say what it costs in hours before anyone commits. Start the read at kultrix.com/contact. A Kultrix engagement is split the same way every time - 70 percent of the hours on design and development, 15 percent on QA and 15 percent on project management - and the team stops growing at the point where coordination eats the gain.

Both. Native iOS work is Swift, with SwiftUI as our default for new apps. UIKit remains the right choice for complex custom UIs, existing UIKit codebases and minimum deployment targets below iOS 14, and our developers handle UIKit/SwiftUI interop in hybrid projects as well as migrations from UIKit to SwiftUI. The iOS team and its stack: kultrix.com/hire/ios-developer. Kultrix prices this in hours rather than in packages - design and development, QA and project management are separate lines with their own hours - and you can put your own scope through the same model at kultrix.com/cost-calculator.