aliessayli2 wrote
this app is not in the google store , I wouldn't risk it.
Ofcourse it's not. Why would Google let an app that makes you download Youtube video in the Playstore. Such apps don't exist in the Play Store, because the store has specific requirements which they don't meet.
You can know if the app is safe by its popularity, frequent updates and the permissions you provide it.
Many good apps aren't in the Play Store, like:
CyanogenMod installer
TV Portal
Pocket Player
WiFi Kill
Router Keygen
AdBlock
Amazon Store
and many many more.
Besides. I use it.