Custom iOS app development for SMBs & Startups

You need an iPhone app that your customers will love. We're the Swift and cross-platform developers in Denver who can build it right the first time—no drama, no excuses, just clean code and smart design.

Business professional reviewing information on an iPhone while working at a desk, representing how SMBs use custom mobile apps in their daily operations.
303 Software iOS developer testing a mobile app on an iPhone while working on a laptop in the Denver office.
Custom iOS app interface designed by 303 Software displayed on multiple iPhone screens, showing clean mobile UI and real product examples.

Why businesses work with us

We're not just another dev shop. We're the team that actually answers your calls and ships on time.

We know iOS inside and out.

Swift, SwiftUI, all the Apple frameworks—we speak fluent iOS. Your app will run smooth as butter and use every trick Apple's got up their sleeve.

Built for real businesses.

Healthcare? Fintech? We've been there. Your app will be secure, scalable, and ready for whatever compliance acronym you throw at us (HIPAA, SOC 2, PCI, you name it).

We ship fast, period.

No missed handoffs, no communication gaps. Our hybrid U.S. + offshore team works across time zones to keep your project moving while you sleep. You’ll always have a responsive local contact and a global delivery team that ships on time—every time. Think of us as your technical co-founder who actually knows how to navigate iOS development.

303 Software leadership team collaborating during a strategy meeting in the Denver office.

How we build your iOS app

We Figure Out What You Actually Need

First, we sit down and talk—really talk—about your business, your users, and what success looks like. No assumptions, just straight questions and honest answers.

Design That Makes Sense

We create interfaces your users can figure out without a manual. Clean, intuitive, and yes—it follows Apple's guidelines so we can navigate getting accepted to the App Store.

Build It Right, Test It Hard

Our Swift developers write clean code that works. We test on real devices (not just simulators) because that's where your customers will use it.

Launch and Keep It Running

We handle the App Store submission headache for you. Once it's live, we stick around for updates, fixes, and making sure your app keeps pace with iOS changes.

The iOS tech we're fluent in

Here's the toolkit we use to build apps that don't crash at 2 AM.

Swift & SwiftUI

Modern, safe, and fast programming for iOS

Xcode & TestFlight

Professional iOS Build, Testing, and Deployment Workflow

CloudKit & Core Data

Secure iOS Data Storage, Sync, and Cloud Integration

Core ML & ARKit

AI-Powered and Augmented Reality iOS Features

Combine & Async/Await

High-Performance iOS Concurrency & Reactive Programming

Keychain & Biometrics

Secure Authentication with Face ID, Touch ID, and Keychain Storage

HealthKit & HomeKit

iOS Integration for Smart Home & Health Data Apps

Apple Pay & StoreKit

In-App Payments, Subscriptions, and Mobile Checkout

Apps for your industry (we've probably built one)

Whatever your business does, we can build an iOS app that makes it better.

Secure healthcare apps clinicians actually use

HIPAA-compliant apps that actually work in a hospital. Telemedicine, patient portals, health tracking—we build apps that medical professionals and patients want to use, not just tolerate.

Fintech apps your CFO will trust

Banking apps with bulletproof security. Real-time trading platforms that don't freeze. Digital wallets that actually work with Apple Pay. We know money apps can't afford to fail.

Shopping apps that convert

AR try-on features that actually work. Checkout flows that don't make people rage-quit. Inventory systems that stay in sync. We build commerce apps that turn browsers into buyers.

Learning apps kids (and teachers) love

Educational apps that work offline when the WiFi inevitably fails. Progress tracking that makes sense. Virtual classrooms that don't feel virtual. Learning should be engaging, not endured.

But what about cross-platform?

Not every app needs to be purely native—and that’s where our cross-platform foundation shines. We’ve evolved a custom Kotlin Multiplatform (KMM) management layer that handles the heavy lifting—networking, data synchronization, and platform-agnostic logic—so we can focus on what really matters: crafting pixel-perfect user experiences on both iOS and Android.

Our KMM core isn’t just code reuse; it’s a performance-optimized starting point designed for speed, scalability, and consistency. Whether we’re building for a startup validating an MVP or a regulated enterprise deploying at scale, our framework accelerates development and reduces technical debt without compromising native feel or reliability.

By combining our KMM foundation with native UI layers and platform-specific integrations, we deliver apps that look, feel, and perform like they were built just for that device—because, in all the right ways, they are. It’s the best of both worlds: shared efficiency underneath, and tailored polish on top.

Illustration of cross-platform mobile app development showing Android and iOS devices connected by shared code.

Let's Build Your App

Stop planning. Start building. We're ready when you are.

The Questions You're Actually Thinking

Let's address the elephant in the room (or the app in the phone)

Okay, but what's this really going to cost me?

Straight talk: Simple apps run $25K-50K. Complex enterprise stuff? $75K-250K+. We'll give you a real number after we understand what you need—not some vague "it depends" nonsense. First conversation is free, and we'll tell you if your budget works or if you need to rethink things.

How long until I can download my app from the App Store?

Basic apps: 3-4 months. Complex ones: 6-12 months. But here's the thing—we ship working versions every two weeks, so you'll see progress constantly. No disappearing for months and then surprising you with something you hate.

Should I go native iOS or save money with cross-platform?

If you want the best iOS experience—smooth animations, all the latest Apple features, apps that feel "right"—go native. If you need Android too and your budget's tight, we can do React Native or Flutter. We'll be honest about the trade-offs either way.

What happens after launch? Do you just disappear?

Nope. Apps need maintenance like your car needs oil changes. Figure 15-20% of initial cost per year for updates, bug fixes, and keeping up with iOS changes. We offer support packages, or we can train your team. Your call.

Will you deal with Apple's App Store review nightmares?

100% yes. We handle everything—writing descriptions, creating screenshots, dealing with rejection feedback (it happens), and getting your app approved. We've done this hundreds of times. Apple's quirks don't surprise us anymore.

Why you instead of a fully offshore team that's half the price?

Because you can actually call us at 3 PM on a Tuesday and get an answer. Because we've been doing this for 19 years and haven't disappeared yet. Because when something breaks (it always does eventually), we're in your time zone fixing it, not asleep on the other side of the world. You get what you pay for.

Need more information?

Our team is ready to answer any additional questions you might have