Media Scanner - update gallery description

This is a small tool to force Android to scan public media directories, and recovery missing items in gallery / music / video apps.
It can help to resolve the issue that, some pictures or musics are in photo or music folders, but won't show up in Gallery app or Music app.

This tool scans Android public directories, include DCIM / Movies / Music / Pictures folders, to list all files, compares with existing items in Android MediaStore, then triggers Android MediaStore scan procedures for missing files.
So if your photos, musics or videos, are in expected folders, but they won't show up in apps, this app is the right tool to resolve the issue.

It has no UI. After being started, it will do its work in background, then quite. You may schedule a regular job to execute it with Init script runner -- autoexec @ https://play.google.com/store/apps/details?id=org.gemini.init, or other job schedulers.

Though this app itself has a very small footprint, only several kilo bytes of storage, and several mega bytes memory usage, the MediaStore scanning service it triggers is not a cheap procedure. So it's not a good idea to start this app too frequently. And I do not want an icon to enlarge the size of this app, so the default icon is transparent.

The only permission required by this app is READ_EXTERNAL_STORAGE, which is required to list existing media files.

Note, if your media files are not in the default folders, this app won't help you. Since it won't randomly search in entire file system. According to the hardware / manufacturer configuration, the default folders may be various, but usually they should be,
- /sdcard/Music for musics
- /sdcard/DCIM for photos
- /sdcard/Pictures for other pictures
- /sdcard/Video for videos (Some may just be put into DCIM folder)

This is an open source project, you can find the code @ https://github.com/Hzj-jie/android-media-scanner.