Ritterfeld — Freelance Mobile App Developer · 2016–present

Experience.

Mobile apps and platforms I've worked on, from business mobility to connected devices.

Client engagements

Flender

AIQ

React Native Engineer

Modernised a React Native app, migrated JavaScript to TypeScript and improved Bluetooth connectivity.

Louwman

Freddi

React Native Engineer

Built the Freddi mobility app with React Native and native mobile integrations.

Reisbalans

Reisbalans App

React Native Engineer

Built the Reisbalans app for business travel and expenses; added UI tests and Bitrise CI.

Kermi

X-Center

.NET MAUI Engineer

Built heat-pump controls in C# and contributed to the Xamarin-to-MAUI migration.

VHS

Education platform

iOS Engineer

Extended an education platform in Swift and Objective-C.

DigiOnline

WebWeaver

React Native Engineer

Built a Windows learning app with React Native Windows, TypeScript and C#.

TRUMPF

ServiceApp

Mobile Engineer

Extended an industrial service app with Xamarin/MAUI, push notifications and OAuth/SSO.

Otto Dörner

TankApp

Mobile Engineer

Maintained a Xamarin enterprise app, including distribution, UI and client/server changes.

OASE

EasyControl / OASE Control

Mobile Engineer

Built a Xamarin/C# app connecting to hardware via Bluetooth and Wi-Fi.

Insight / Microsoft

SharePoint-integrated app

React Native Engineer

Built an iOS and Android React Native app with SharePoint integration.

ARAG

Consultation app

iOS Engineer

Extended an internal Objective-C iOS app for customer consultations and contracts.

Deutsche Bank

Banking app

iOS Engineer

Built Swift banking features for trading and eSafe documents.

Reware

Care documentation app

Mobile Engineer

Built a Xamarin/C# app for daily care documentation.

Earlier mobile work

Jinn

Jinn & Jinn Delivery

iOS Engineer

Developed customer and courier iOS apps, including UX and design.

ITSonix

BeatClip

Mobile Engineer

Worked on the mobile app and backend using Xamarin, Java and Objective-C.