Mobile App Development

We recommend a native build in Swift (iOS) or Kotlin (Android) when the app needs capabilities that Flutter's platform channels cannot cleanly abstract: background health sensor streaming via Apple HealthKit, Bluetooth Low Energy peripherals with complex custom profiles, CarPlay or Android Auto integration, or platform-specific AR using ARKit or ARCore at a low level. For these cases, we build the affected module natively and, where both platforms are needed, maintain two separate native projects. We are transparent about the cost difference upfront. Native dual builds typically add 35 to 50% to the build budget compared to an equivalent Flutter project.

A focused app covering three to five core screens with a REST API backend typically reaches a testable beta in six to eight weeks. A mid-complexity app with user authentication, payment integration, push notifications, and an admin panel runs ten to fourteen weeks. Enterprise apps with offline sync, complex business rules, or hardware integrations can extend to four to six months. These are build timelines, not calendar timelines. App Store review adds one to three business days, and Google Play review adds one to two business days after submission. We give you a milestone schedule in the BRD, not a single delivery date.

Yes, fully. For the App Store, we configure App Store Connect, prepare screenshots at all six required iPhone sizes plus iPad if applicable, write the app description and keyword field, complete the privacy manifest, and submit for review. For Google Play, we configure the Play Console, prepare the feature graphic and screenshots, write the store listing, complete the data safety form and content rating questionnaire, and release to the production track. If Apple or Google raises a review issue, we respond and resubmit. This is included in the project cost, not billed separately.

Most of our mobile apps connect to an ASP.NET Core or NestJS backend that exposes a versioned REST API over HTTPS. Authentication is handled with JWT tokens, and sensitive data is stored in PostgreSQL or SQL Server with encrypted columns for PII fields. We also build a companion web panel in Next.js for operations or admin teams who need to manage data without going through the mobile app. Push notifications are delivered via APNs (Apple) and FCM (Google). If you already have an existing backend or a third-party API, we integrate against it rather than rebuilding.

Yes. We build iOS and Android apps for UK companies, delivered remotely, usually from one Flutter codebase that ships to both stores, with UK or EU data residency available and GDPR-aligned handling of user data. Most projects include a matching admin panel so your team can manage bookings, users and reports in one place. Our custom software development company in the UK service covers the wider UK offer.

For most business apps, such as customer portals, field workforce tools, ecommerce, and SaaS companions, Flutter cross-platform development is the correct choice. Flutter compiles to native ARM code, produces a single codebase for iOS and Android, and ships features on both platforms simultaneously. Native Swift (iOS) or Kotlin (Android) development is warranted when the app requires low-level hardware integration: health sensor streams, custom Bluetooth protocols, ARKit/ARCore, or specialized camera pipelines unavailable through Flutter plugins. We make this recommendation after reviewing your feature requirements, not as a default.

Yes. Timeline Digital manages the full submission process for both Apple App Store and Google Play, including provisioning profiles and signing certificates, privacy manifest compliance (required from iOS 17+), screenshot sets for all required device sizes, localised store listings for US, UK, German, and other markets, and review response handling. Every release candidate goes through internal QA and a TestFlight or Play internal testing track before the public submission is filed.

Compliance is addressed at the design stage, not added afterward. For GDPR: data collection is limited by purpose, consent flows are built into onboarding, and a data deletion API is included. For HIPAA: PHI fields are encrypted at rest using device-level Keychain/Keystore APIs, connections use certificate pinning, and audit logs record every data access event. Payment card data is never stored in-app. Stripe or Braintree SDKs handle tokenization so the app never touches raw card numbers and PCI scope is minimised.