SUMMARY It would be nice to have reference in Gwenview to Showfoto. Many distros do not preinstall applications like Showfoto (Digikam nor Krita) and for average user it would be useful to point that those image editor(s) are just click away and do exist. There are other cases in KDE ecosystem that do something similar - Spectacle, Dolphin ... Whether this is done through menu, context menu, toolbar... I leave to your preference. SOFTWARE/OS VERSIONS OS: Kubuntu 20.10 ADDITIONAL INFORMATION: Funny thing, after a couple of years actively using KDE it is only recently that I heard of Showfoto. It just never came up. Be advised though, Digikam is generally not perceived as image editor.
Discover is an app meant for this purpose; you can find ShowFoto there. However the KMoreTools functionality basically exists for this, and exists for the purpose of letting people discover slightly related functionality in an app itself. Perhaps it could be leveraged here.
(In reply to Nate Graham from comment #1) > Discover is an app meant for this purpose; you can find ShowFoto there. Sorry, but Discover is not much of a help in this situation. Searching for "Image editor" in Discover > Applications > Graphics, ShowFoto came up on 40th place. As stated in this post, it is not the case only for Kubuntu 20.10. https://www.reddit.com/r/kde/comments/hauwf4/searching_in_discover_am_i_doing_something_wrong/