Flutter & native iOS apps, built, modernised and maintained.

Proper Bits is Alexander Kirsch’s software company in London, building and maintaining Flutter and native iOS apps for start-ups, product companies and agencies.

Get in touch See services

MOIA: lead engineer, Flutter app
Haiilo: branded-app build automation
HeKu IT: three contracts, 2016–25
Weeklie: 2.5M iOS downloads

Open source

A code generator the Dart ecosystem builds on

I maintain copy_with_extension. Add @CopyWith() to a Dart class and it writes the copyWith code Flutter developers otherwise write by hand.

The Dart team’s build_runner documentation lists it among the most-used code generators, and OpenAPI Generator’s Dart client template adds it to clients that use json_serializable.

50+published packages depend on it
160/160pub.dev points

pub.dev GitHub How it started

@CopyWith()
class User {
  final String name;
  final int age;
  // …
}

user.copyWith(age: 42);

Work

Selected contracts

MOIA

Lead Software Engineer

2020–21

Lead engineer, focused on Flutter, on the app MOIA’s drivers and service staff use to run Volkswagen’s ride-pooling service in Hamburg.

Haiilo

Senior iOS Developer

2021–22

iOS development in Swift on Haiilo’s employee-communications app, and the build and release automation behind its branded-app line: every customer app generated from one codebase.

HeKu IT

Senior Software Engineer

2016, 2019–25

iOS and Flutter development, maintenance and technical reviews for a Munich software company’s own products and its clients.

Earlier: a regulated UK health-tech iOS app, lead iOS engineer at a US social-video start-up and founding developer of a Flutter nutrition-tracking app.

About

Hello, I’m Alexander

I’ve built mobile apps on contract since 2014, for start-ups, established product companies and the agencies that serve them, and since 2025 through Proper Bits, in London.

Objective-C and Swift came first, and native iOS is still half of my work; Flutter is the other half. The part I care about most is what happens after launch: tests, release pipelines and code the next developer can read.

For agencies and procurement: a one-page profile to print or forward.

Services

How Proper Bits can help

Inside your team, on a fixed scope or as a second pair of eyes.

Contract development
Day-rate Flutter and iOS work inside your team, alongside your engineers: features, releases and the unglamorous work that keeps an app healthy.
Fixed-scope builds
A defined app or feature, delivered for an agreed price.
Technical advisory
Architecture reviews, build-versus-buy decisions and help hiring a mobile team.
Code audits
A written report on your Flutter or iOS codebase, every finding ranked by risk and effort.
Taking over and modernising apps
Picking up an app from a previous developer, stabilising it and bringing it up to current SDKs.
Maintenance retainers
A few hours a month to keep an app current, compliant and shipping.
Mobile CI and release pipelines
Fastlane, GitHub Actions and self-hosted Mac runners, set up and documented.