Only current app is displayed on the top Gnome panel
Gnome has become the main UI in too many Linux distros and I honestly believe it harms Desktop Linux popularity all these years. People try Linux, people see Gnome 3, people hate it, and they are done with Linux. If you are completely good with "just for fun" conception, just keep it as it is, hopefully KDE will replace Gnome in future in popular distros. But if you wish Linux and Gnome only the best, please listen to what I am suggesting. Gnome 3 has been criticized from the very moment it has been released and there are certain reasons for it. It's depending on hotkeys and touch input too much, however most users on PCs are used to mouse input. Please consider improving mouse interaction out of box. I believe you should take responsibility for it, instead on depending on gnome-tweaks and addons and polish the feature yourself. The space on top panel is not rationally used, it could and I believe it should contain all the running apps like it happens on all many popular UIs. Just put date and time to the right corner and you'll have plenty of space for all the running apps within this workspace. I understand that this is what you were against all these years but this is the common way the things are done in interfaces. By going against it, you go against common knowledge the users bear - so you go against ergonomics. You could leave an option in settings to go current Gnome 3 way or THIS classic way - the general ergonomics of Gnome 3 will be much improved and won't hurt by all means. I believe any independent ergonomical test will confirm it. Gnome 2 was a wonderful UI, the best of it's time from my point of view. Gnome 3 is hated by many people. It's up to you to make Gnome 3 once more the interface that don't bring that much frustration and distress.
p.s. one more thing, I understand the conception of addons but as an ergonomist I understand that no many users especially non-power users won't come to a point with experimenting with addons. Many would rather return to Windows or Macs they are used to. So considering everyday user I always think about basic functionality. Some things should work out of box. Thanks for reading. And sorry for criticizing your work, no one likes critics (especially knowing that there are so many people that DO like gnome 3), but you and your work is TOO important for Linux world now, so please rethink certain things and consider making a step towards everyday users with common knowledge... I mean those users that don't like current Gnome 3 ways. Even if you truly want such users to learn your conception of working with desktop (hotkeys I mean) the best strategy to do it - is to attract them first with the availability of a more familiar workflow. If your way is really good - eventually they will start using it instead of using a mouse.
Have a nice day.