Twofingers Apps

Apps with passion
10 years app experience
I have been developing apps as full-stack developer for Android and iOS since 2010. Meanwhile I am looking at over 1 million app downloads and thousands of satisfied user reviews.
Technologically Up-to-date
It is my ambition to always be technologically up-to-date. The constant development of my own apps allows me to immediately back up new technologies and standards with practical experience.
Your idea-realizer
With many years of broad expertise and great passion for apps in general I will support you from feasibility analysis over conception to development and release management of your apps.


Trader Radar
Notifies about the publication of insider trades in the USA and Germany in near real-time. The knowledge of insiders in your pocket.
What's it worth on eBay?
Finds the current market value of items in seconds. Perfect for private and professional sellers.
Crystal Math
A different kind of brain teaser. Mental arithmetic against the clock - along with duels against friends and daily high score list.


Rafael Kolloch
With over 20 years of programming experience from web over backend to mobile apps, I look back at a rich set of skills in various disciplines. Being a team-player and open communicator I am wholeheartedly looking forward to engage in your project and help you lead it to success.

Fields of expertise

Analysis, consulting, architecture, development, app store management


Automotive, banks, logistics, lottery, public services, retail, utilities, insurance

Programming languages

Java, Kotlin, Objective-C, Swift, PHP


Android Studio, IntelliJ IDEA, Xcode, Eclipse, Netbeans, Visual Studio Code

Android skills

Android SDK, Kotlin Multi-Plattform, AndroidX, Android Jetpack, Koin, Dagger2, Coroutines, MVVM, MVP, MVI, Room, LiveData, SQLite, SQLCipher, Retrofit, OkHttp, Gson, Firebase (Ads, Cloud Messaging, Crashlytics, Realtime Database, Remote Config), Admob, Glide, Picasso, Timber, Material Design UI, Google Human Interface Guidelines, Biometrische Authentifizierung (Fingerprint), Gradle, Unit Tests, JUnit, Mockito, MockK, Robolectric, Release Management

iOS skills

AF Networking, CocoaPods, CocoaLumberjack, Firebase (Ads, Crashlytics, Cloud Messaging), Release Management

General skills

Regular Expressions, Reverse-Engineering, Pentesting, Web-Scraping

Project-management / CI

SCRUM, Atlassian Toolchain, JIRA administration / customization, Bitbucket, Jenkins, TeamCity, SonarQube


avanCode GmbH
Speziell die Entwicklung von Apps für die iOS Plattform geschieht in Zusammenarbeit mit den Kollegen von avanCode. Als eingespieltes und erfahrenes Team sind wir in Rekordzeit produktiv bei der Umsetzung Ihrer Multi-Plattform App Projekte.
growth project UG
Mit der growth project UG aus Hamburg realisiere ich innovative Lern- und Schulungsplattformen. Zusammen arbeiten wir daran e-Learning Konzepte in alle Bereiche der betrieblichen Weiterbildung zu bringen.