At Zappware I got the chance to contribute to their "One-TV" platform. It is basically an ecosystem of different client devices (web, android, ios, STB, ...) that allow the user to discover and play content from different sources. You can compare it a bit with netflix, but then with additional content from regular television channels.
I myself worked mainly on the web client. More specifically I worked on the login/first install flow, the displaying of and navigating through the content, settings screens, restricting parental rated content, the ability to buy/rent/subscribe and many other features.
Overall it was a very cool experience to never forget!