This app takes full advantage of Lollipop's Camera2 API, and therefore requires it to be properly implemented in your Android ROM. If your device runs on Lollipop, and still the app is not compatible with it, please contact your ROM provider (e.g. Samsung, LG) and ask them why they haven't implemented Camera2 API? So far the situation looks really bad. Only Nexus 5 works perfect. Nexus 6 is almost perfect (only white balance is not working). But the rest of manufacturers are not willing to take this effort, and therefore their devices are not compatible at all.