we want something simple like plume with more features and good RTL support.

Ghost in my tests had some problem with RTL

we dont need that much feature :)

yes but unfortunately it still lacks some features that we need, for example in my tests it had problem with bidi text.

those softwares are released with their own installer ( davinci resolve for example )

perfect

there is a store for them called appimage pool which is written in flutter and its also an appimage itself. https://appimage.github.io/AppImagePool/

yes appimages are good but my problem with them is that when there is a new version i should download them again and again....

yes flatpaks are great but their only downside is the download size of an application

aur is limited to arch based distros only

but what about the apps that are not in the official repository?

for example tuba the mastodon client

no they just decided to make 4.0 into 40