Mobile app development
iOS and Android apps that ship secure, on a fixed price
Most apps are built fast and secured later, usually after a customer's security review fails or a researcher emails about an exposed API key. We build yours so that conversation never happens, and we hand you the pentest report on launch day.
- Fixed-price proposal within 48 hours
- You own 100% of the code
- Pentest report included at launch
The problem
Why most builds disappoint
A mobile app is a binary you hand to every attacker on the planet. Anything inside it, an API key, a feature flag, an admin endpoint, a hard-coded test account, can be extracted in an afternoon with free tools. Most of the mobile breaches we see in testing were not clever. They were secrets shipped in the bundle and APIs that trusted the client.
We are a security firm first. That means the app is designed around what an attacker can see from day one: no secrets on the device, every authorization decision on the server, tokens in the Keychain and Keystore rather than plain storage, and certificate pinning where it earns its keep.
It also means you get something agencies cannot give you: an independent penetration test of the finished app, run by the team that tests SaaS products for SOC 2 and ISO 27001 audits. When your first enterprise customer sends a security questionnaire, you already have the answers.
The difference
A typical agency, and us.
| Typical agency | innsecs | |
|---|---|---|
| Pricing | Hourly, open-ended, estimates that drift | Fixed price per phase, held in writing |
| Visibility | A demo at the end of each month | A new build on your phone every week |
| Security | Assumed, or bolted on after launch | Designed in, then penetration tested |
| App Store review | Your problem after handover | We submit, handle rejections, and ship |
| Ownership | Code held until the final invoice | Your repository, your accounts, from day one |
What we build
From first version to products that scale.
MVPs that test a market
The smallest version of the product that can prove or disprove the idea, scoped ruthlessly and shipped in weeks rather than quarters.
Cross-platform apps
React Native or Flutter when one codebase serves both platforms well, which is most of the time. You pay for one app, not two.
Native iOS and Android
Swift and Kotlin when the product needs deep platform features, heavy on-device processing, or performance a shared codebase cannot reach.
Backends and APIs
The server the app talks to: authentication, data, payments, push notifications and admin tooling, built with the same authorization rigour we test for.
Fintech, health and regulated apps
Apps that handle money, health data or children's data, built with PCI DSS, HIPAA, GDPR and COPPA requirements in the architecture rather than the backlog.
Rescue and hardening
An existing app that is slow, crashing or failing security reviews. We audit it, tell you honestly whether to fix or rebuild, then do whichever makes sense.
Secure by default
Built by people who break these for a living.
We spend most of our week finding vulnerabilities in other teams’ products. Everything we learn goes into what we build for you.
No secrets in the binary
API keys, signing secrets and third-party credentials live on the server. The app holds only short-lived, user-scoped tokens that are worthless when extracted.
$ strings app.ipa | grep -i key // nothing worth stealing
Server-side authorization, every time
The app is treated as hostile. Every request is authorized on the server against the user's actual permissions, so a modified client gains nothing.
Secure storage and sessions
Tokens in the iOS Keychain and Android Keystore, biometric unlock bound to the hardware, sessions that expire and can be revoked remotely.
Transport and pinning
TLS everywhere, App Transport Security enforced, and certificate pinning on high-value apps where the operational cost is justified.
Dependency and supply chain hygiene
Every SDK reviewed for what data it collects and sends. Automated vulnerability scanning on every build, and a software bill of materials at handover.
Independent pentest before launch
The finished app and its API tested against OWASP MASVS by our testing team, findings fixed, retested and reported, before the first real user installs it.
How it works
From call to launch, no surprises.
- 01
Scoping call and fixed quote
Week 0
Thirty minutes on what the app must do, for whom, and by when. Within 48 hours you get a written proposal with a fixed price, a timeline and what is explicitly out of scope.
- 02
Product design
Weeks 1–2
User flows, wireframes and a clickable prototype you can put in front of real users before a line of production code is written. Threat model drafted alongside.
- 03
Build in weekly increments
Weeks 3–10
A new build on your phone every week through TestFlight and Google Play internal testing. You see progress, react early, and nothing is a surprise at the end.
- 04
Penetration test and hardening
Final 1–2 weeks
Our testing team attacks the app and its API like an outsider would. Findings are fixed and retested. You get the report, ready for customer security reviews.
- 05
Store submission and launch
Launch
We prepare listings, privacy labels and review notes, submit to both stores, and handle any rejection until the app is live.
- 06
Support and iterate
After launch
Thirty days of included support for anything that breaks. After that, an optional monthly retainer for new features, OS updates and monitoring.
Our stack
- Cross-platform
- React NativeExpoFlutter
- Native
- SwiftSwiftUIKotlinJetpack Compose
- Backend
- Node.jsTypeScriptPythonPostgreSQL
- Cloud
- AWSGoogle CloudFirebaseSupabase
- Payments and auth
- StripeApple PayGoogle PayOAuth / OIDC
Packages
Fixed prices, published.
Starting points, not traps. Your proposal confirms the exact figure after a free scoping call, and that figure does not move.
MVP
Validate an idea with real users, fast.
6–8 weeks
- Cross-platform app for iOS and Android
- Core user flows, authentication, one integration
- Backend and admin panel
- Security baseline and automated scanning
- App Store and Google Play submission
- 30 days of post-launch support
Launch
A production app you can sell to businesses.
10–14 weeks
- Everything in MVP
- Product design and clickable prototype
- Payments, push notifications, analytics
- Threat model and MASVS-aligned build
- Independent penetration test with retest
- Customer-shareable security attestation letter
Scale
Complex, regulated or high-traffic products.
Phased
- Everything in Launch
- Native iOS and Android where justified
- HIPAA, PCI DSS or GDPR-aligned architecture
- SOC 2-ready logging, access control and evidence
- Load testing and observability
- Dedicated team and monthly roadmap
Something bigger or different? Tell us about it and we will scope it properly.
Our promises
In the contract, not the brochure.
Fixed price, held
The figure in your proposal is the figure you pay. Change requests are quoted before they are built, never invoiced afterwards.
You own everything
Your GitHub organisation, your App Store and Play accounts, your cloud account. If we part ways tomorrow, you keep the whole product.
Weekly builds or we say why
A new build on your phone every week. If a week slips, you hear it from us first, with the reason and the recovery plan.
Ships tested
No launch without an independent penetration test and every critical and high finding fixed. It is in the contract, not the brochure.
Most MVPs we build land between $14,000 and $30,000. Production apps with payments, integrations and a full security test typically run $32,000 to $60,000. You get a fixed figure in writing before any work starts, so there is no guessing.
Six to eight weeks for a focused MVP, ten to fourteen for a production app. The scoping call tells you which, and we will say so plainly if the date you have in mind is not realistic.
Cross-platform for most products, because one codebase halves the cost of every future change. Native when the app genuinely needs deep platform features, heavy on-device processing or the last ten percent of performance. We recommend on merit and explain the trade-off.
Because security is cheapest at design time and most expensive after launch. Fixing an authorization flaw in a shipped app means a rebuild, a store review and a disclosure. We prevent the flaws we spend the rest of our time finding in other people's apps.
Yes, from the first commit. It lives in your repository, deploys to your cloud account and publishes under your developer accounts. There is no lock-in and no licence fee.
Thirty days of support is included. After that you can take the code in-house, bring another team, or keep us on a monthly retainer for features, OS updates and security monitoring.
Get a fixed price for your project in 48 hours.
Tell us what you want to build. We will scope it properly, quote a figure that does not move, and tell you honestly if the timeline you have in mind is realistic.
No sales sequence. A scoping call and a written proposal cost nothing. See published pricing first if you prefer.