The Quit All will close all the running applications at that time. If the app you want to quit is not running, then the app won't have any effect. Quit All has been tested and it can't remove all the apps. If you want to manually close the Mac Informer app, right click it and choose Quit. However, I wouldn't recommend closing it since it provides relevant updates to your installed apps. I have also checked its memory footprint and it's very low on system resources which means it won't affect your work at all.