- Intrusive ads
- Snake oil
- Naughty Devs
Cleaner Master, sometimes called Clean Master does nothing to your useful to your phone. RAM cleaning on android is not useful and the “junk files” it cleans are cache files that will either be downloaded again or created again.
Safe alternatives: Android cleaners are redundant, android does housekeeping by itself. That said, SD Maid or Ccleaner are good apps