@OP I hate to be a douche but your phone has only 512 RAM and it's going to run into performance issues when running Drastic, you can try closing all other apps in the background then launch Drastic but I doubt it would help, Maybe if your device was quad core, 1GB RAM it should run smoothly.
Before you launch Drastic make sure you close all other apps in the background to free up RAM on your android device. This happened to my phone after latest update arrived but can easily be fixed.
You're not the only one having this issue, it might be the latest update causing this or you got a bad ROM, find one that works on Google or try turning off Multi-threaded 3D Rendering if that helps.