The Storage Check app displays details about app data size and memory usage. There are no limitations for the apps data size on Lumia with Windows Phone 8, so they can grow as much as needed. This is why we offer details on the app sizes with the Storage Check app. With the Storage Check app you can clear several types of temp files, such as leftovers from app installs and updates, SkyDrive uploads and PC file transfers. They are removed by the OS too, but sometimes quite slowly. First version of the Storage Check app does not separate, measure or clear video files. Shot videos count towards Photos, and downloaded or side-loaded videos count towards Music+Videos.
Note: The Storage Check app does not clear all files from the Other folder. This folder contains multimedia metadata, file system overhead, and in general things that the user cannot do much about.