So I kicked off adding 3rd party applications to Fedora Workstation 28, by submitting two tickets proposing NVidia driver and Steam. 

There are basically two pages to look at:

And the practical guide for proposing an application at:

The second link includes a proposal template for adding apps. The vehicle for proposing applications is the working group pagure instance.

I would recommend people to go over the requirements and work with 3rd parties to propose further applications to include. We accept package proposals that are either in RPM or Flatpak format.

Also we have a detailed howto created for how to create your repository technically ready for inclusion in Fedora, but it needs a little more work to get online, but Paul Frields is working on that and hopefully we will get it resolved soon.

Christian