through much trial and error, I am now "Activation Screen" Free.
Here is a list of what to do:
Download "root uninstaller" from Play store..(the version you need shows an Android Icon)
Use it to remove ALL Sprint related processes/APK's
Reboot your phone
This worked on mine, hope it works on yours.
Mine is rooted, s-off, TWRP flashed, and Custom "Bad Boys" Rom