Got this phone https://www.ebay.ca/itm/332297469860 12MP camera good price
to know :
power+home+volume up = recovery mode
power+home+volume down = odin mode/download mode
Install Odin (Need windows) http://www.stechguide.com/install-twrp-recovery-samsung-galaxy-s5/
Back to Linux
Have to be in developper mode first or adb won't work.
After successfull install,
Install Fdroid apk from original website (for open source apps)
And Yalp store, for the play store apps
Got another one, this time spending too many hours without any luck.
I am trying a high success rate way :
once TWRP is installed you can pretty much do anything without hassle (install custom rom, format, restore, backup, etc).