FinalCrypt- an open source file encryption application

[crosscourt]

More here, https://itsfoss.com/finalcrypt/

[Rademes]

Looks like good application for mass encryption if you need to encrypt many files. The only drawback is, you need to keep safe your USB flash drive with keyfile. Or use special flash drives with digit combination lock.
Like this one https://www.kingston.com/en/usb/encrypt ... ity/dt2000

[crosscourt]

After an incident with my wife Ive secured all our USB flash drives since.