Service · Mobile + custom application development
Mobile applications tailored to your business goals — iOS, Android, and hybrid builds with intuitive UI/UX and consistent performance on every device. An award-winning cross platform mobile app development company: 14+ years, 500+ apps shipped. Strategy, design, engineering, and post-launch support — one senior team, no handoffs.
Our expertise
Four ways to build a mobile app — and picking the right one matters more than the build itself. Native for platform-heavy products, a shared codebase for speed to both stores, hybrid when content changes faster than the app. That's the real job of a custom mobile app development agency: recommending what fits, then maintaining it for years.
01 · Native iOS
iOS-first builds when iPhone or iPad is the primary device. Our custom iOS app development services extend to Apple Watch and tvOS when the engagement calls for it. Direct access to platform features, no abstraction layers.
02 · Native Android
Android-first builds for Android-heavy markets or device-specific use cases, from a custom Android app development company that treats Android as a first platform — not a port target. Material Design 3 by default. Wear OS and Android Auto extensions when needed.
03 · Cross-platform
One codebase, two platforms when the use case justifies it. Cost-efficient when feature parity matters more than platform-specific polish.
04 · Hybrid apps
Content-heavy apps, internal tools, and MVPs where shipping fast matters more than native performance. Content updates roll out server-side, without waiting on app-store review cycles. One codebase your existing JavaScript team can own.
Capabilities
As a committed custom mobile app development agency, OpenSource Technologies (OST) keeps senior experts involved from scope to launch. The team that plans your engagement is the same team that builds, tests, and ships it. No bait-and-switch. No rotational handoffs at handover.
User research & UX
User interviews, competitive analysis, information architecture, and high-fidelity Figma prototypes. Accessibility-first practice, WCAG 2.2 AA + Section 508 conformant.
Backend & APIs
Node, Python, PHP, or Go backends as your stack requires. Strongly typed API contracts, OpenAPI documentation, and integration with the third-party services your app depends on.
AI integration
Knowledge-base-grounded chatbots, recommendation engines, content generation, and predictive analytics. Cost-monitored production deployments, not demo-quality.
QA & release
Unit, integration, and end-to-end tests in CI. App Store and Google Play submission management. Crash reporting and performance monitoring after launch.
The backend is what allows a mobile app to do real work. OST builds mobile backends that support secure logins, user accounts, data storage, business rules, payment processing, reporting, notifications, and admin controls. As a custom mobile app development agency, we connect apps with the systems your business already uses, including CRMs, ERPs, eCommerce platforms, booking tools, analytics platforms, payment gateways, and custom databases.
For companies looking for a cross platform mobile app development company, this integration layer is often the difference between a simple app and a useful business platform. Our team works with REST APIs, GraphQL, SDKs, cloud services, and third-party tools to keep data moving securely between your app, backend systems, and business workflows.
How we work
The phases that apply to every engagement, not just custom mobile app development. The team that scopes does the building, and the operating.
Phase 01 · 2–4 weeks
Stakeholder interviews, technical review of existing systems, risk register, written scope with milestones and exit criteria.
Phase 02 · 3–12 months
Two-week sprints with working demos. Senior leads on every sprint review. Code reviewed, accessibility checked.
Phase 03 · 2–6 weeks
Parallel run with rollback path. On-call coverage during the launch window. Stabilization continues until incident rate trends to zero.
Phase 04 · ongoing
Multi-year retainer with the same team that built the product. Monthly check-ins, quarterly business reviews.
Read the full engagement model on the How We Work page.
Industries we serve
Six core verticals where OST has the deepest engagement experience. Plus nine adjacent industries served on selective engagements.
01
K-12 charter networks, higher education, public sector portals.
02
Donor-cycle nonprofits, advocacy organizations, civic platforms.
03
HIPAA-aware platforms, medical directories, telemedicine adjacency.
04
Multi-tenant SaaS, brokerage tools, self-storage operators.
05
OpenCart specialists, custom commerce, $10B+ in transactions processed.
06
Industrial platforms, B2B safety-tech, embedded engineering teams.
Also serves on selective engagements
Older mobile apps can become slow, difficult to maintain, or limited by outdated technology. OST helps businesses modernize existing apps by improving performance, updating UI/UX, fixing code issues, upgrading frameworks, and rebuilding features that no longer support business needs. For companies looking for a custom mobile app development agency, the work starts with a full technical review of the current app, backend, APIs, database, security setup, and user experience.
From there, we recommend whether the app should be improved in phases or rebuilt on a stronger foundation. Android apps may need updates for newer devices, OS versions, Google Play requirements, integrations, and performance standards. As a custom android app development company, OST helps make those updates without disrupting the core business workflow.
We also support iPhone and iPad app improvements, including App Store compatibility, performance optimization, interface cleanup, and feature upgrades. Our custom ios app development services help businesses extend the life of existing apps while preparing them for future growth.
Launching a mobile app requires more than uploading it to Google Play or the App Store. OpenSource Technologies (OST) supports the full release process, including build preparation, store listing guidance, testing, submission support, version control, and launch checks.
For Android-focused products, our experience as a custom android app development company helps businesses prepare apps for Google Play submission, compatibility checks, device testing, and ongoing updates. After launch, OST can support bug fixes, crash monitoring, OS compatibility updates, performance improvements, feature enhancements, and long-term roadmap planning.
The custom ios app development services include support for App Store requirements, performance review, device testing, and release preparation. This keeps your app reliable, secure, and useful as users, devices, and business needs continue to change.
Frequently asked questions
3 to 12 months from kickoff to first production release, depending on complexity. Pilot and MVP scopes can ship in 8 to 12 weeks. Enterprise builds with deep integrations run 9 to 14 months.
Pilot scope (one platform, basic backend) starts around $40K. Production scope (multi-platform, custom integrations) lands $100K to $250K. Enterprise scope with deep integrations runs higher. Use our modernization cost calculator for a defensible bracket at our blended rate.
Yes. A cross platform mobile app development company can build apps with frameworks like Flutter or React Native that deliver strong performance and a smooth user experience in many business cases. OST reviews your app features, device requirements, integrations, and scalability needs before recommending cross-platform or native development.
Yes. Our default is multi-year retainer with the same senior staff. The senior on your kickoff call is the senior on year-five releases.
Yes. Submission management, store-listing copy, asset preparation, and policy-compliance review. We sit through the rejections and resubmissions so you do not have to.
WCAG 2.2 AA + Section 508 conformance is included in baseline scope, not an upcharge. Audit-ready documentation produced as part of every engagement.
Ready to build?
Multiple ways to start: schedule a discovery call, run our cost calculator for a budget bracket, or use the contact form for a written response.
