This simple program makes changing retroachievements users easier, so there is no need to retype user and password each time, just select a profile, set your username and password and change the profile name if desired.
The release available on github was tested just on a RG35XX SP, for other devices some changes in the code may be needed.
Installation:
1 - Download the latest release (or compile) from RetroArchUserMgr GitHub repo
2 - Extract the zip and copy the contents to your muos applications folder