How to Clear System Storage on Android Phone?

Storage Cleaner of "System Optimizer - Phone Booster & Cleaner Master"

"Clean up storage space" in app "Storage Analyzer - Clean Up & Free up memory"

Find what files are taking up your hard drive space

Storage Manager in app "Storage Space - Delete Duplicate file & Large file"

Clean up storage, Free up ram, phone cooler, delete files and restore deleted files.

"Storage Cleaner" in app "File Explorer - Manage files & Storage Analyzer"

Video describes file permissions of "Storage space & Disk analyzer" application