1. How to uninstall it now? 2. It seems the app changed something in the system settings, so that now, when I lock the screen, it goes off. Before, it started

1. How to uninstall it now? 2. It seems the app changed something in the system settings, so that now, when I lock the screen, it goes off. Before, it started to show the screen saver. How to undo this? 3. You should have provided answers to my questions in your FAQ section, really.