Name: Gamescope (aka steamcompmgr)
Why should this be included in the repository? Because it's an interesting open source project that may stablish a new standard on rendering games in the future.
Is it Open Source? Yes.
Who and how many users do you anticipate will use this software? Eventually, it will be used a lot by gamers such as me.
Link to source tarball/zip file: https://github.com/Plagman/gamescope/archive/3.7.tar.gz
As a side note, this software (formerly known as steamcompmgr) was "abandoned", but now it's development has started again and they changed it's name to Gamescope.
It's my first request, if something else is needed, please let me know.