The following projects are part of my portfolio. Please expand the “Portfolio” menu above to get details about the projects.



Keestash is an Open Source Password Safe currently in active development.


„Recommendation Assistant“, Nextcloud App and Master’s Thesis

Design and Implementation of a File Recommendation System Using
Collaborative Filtering and Content-Based Recommendation for the Nextcloud PlatformShared project (Frankfurt University of Applied Sciences, Nextcloud GmbH)

„Didapptic“, non-commercial, didactic App database

didapptic is a non-commercial, didactic app database from teachers for teachers with numerous mobile apps that you can use in your or for your teaching.
In coorporation with Goethe Universität Frankfurt am Main

„PHPAlgorithms“, algorithm and data structure implementation

A collection of common algorithms implemented in PHP. The collection is based on „Cracking the Coding Interview” by Gayle Laakmann McDowell



Daily used common PHP classes and methods, summarised in a package


„Simple-RBAC“ implementation of „Role Based Access Model“

Simple leightweight PHP Role Based Access Control library



resolving database table dependencies using topoligical graph sorting


„Currency“, Mobile Application (Android)

Summarised daily currency rates from the European Central Bank


„SmokeFree“, Mobile Application (Android)

Saved money and time span since the last cigarette


WP Last Modified

Last modification time stamps in WordPress posts/pages


WP Show On Mobile

Show/Hide content on mobile/desktop clients