As the Clover interface is similar but different from Android, the process for clearing cache and forcing apps to close is slightly different. If you need to clear cache and force stop an app, you'll need to go to 'settings' and then select 'storage' from the left sub-menu. On the right, there will be a section for 'apps', and then things should look the same as the application manager for base Android. Find the app in the list and clear/kill as needed.