Flayers displays wallpapers with adverts in desktop and lock screen of Android phone. Users that allow this collect money for each campaign and can transfer it for their own bank account. Another possibilty to earn cash is to answer polls sent occasionally by admins.
This is one of project that seems to be easy at first glance but then it turns out to be extremely difficult. I was forced to create my own lock screen what is not easy in the Android world with many producents customizations, multiple system versions with differences in security strategy. But to be honest it gave me lot of satisfaction and really increased my skills.
Techniques: HttpUrlConnection, SQLite, Wallpaper Service, Keyguard
Tools: Git, Bitbucket