A Tippspiel is a prediction game where the game results of (football) matches are predicted and varying points given based on the actual result. Starting in 2006, I have been running a Tippspiel every two years for each World Cup and European Championship where approximately 50 users participate for fun. Besides game results, there are also additional questions (for example, which will win the World Cup) allowing to earn bonus points.
The frontend is built with HTML5 and CSS3 and is responsive and supports Retina screens. In the screenshots, you can see how the layout and texts are adjusted for smaller screens and mobile devices while showing the same information.
The backend is built with PHP and MySQL running on an Apache server. The game data is retrieved from a web service (OpenLigaDB) using a REST API and (their older SOAP API) returning JSON. A script is executed periodically by a cron job to retrieve new match results and new fixtures (for the knockout phase).
Skills/Technologies: PHP, MySQL, SOAP/REST API (XML/JSON), HTML5, CSS3, Apache