Here is a simple challenge for Firefox OS. There are already few challenges available on the market place, but I decided to add this one because it’s slightly different from the others (Thx to Gunther for the idea). There’s another crackme around the web using the same idea but it has been released as a single .js file and it’s not so easy. I think that a simple keygenme could be helpful to familiarize with this kind of code obfuscation.
KeygenMe available here: https://marketplace.firefox.com/app/zairons-firefox-os-keygenme
If you are lazy to install Firefox OS simulator you can get the KeygenMe from here: Firefox OS KeygenME