Shortcut Composer allows you to create additional palettes on it in addition to the existing popup palette, and these can include brushes, tools, blend modes and more, I’ll spare describing all the possibilities here, best you check it out:
My favorite plugin is “Krita-UI-Redesign”, this offers the possibility to have the toolbox and the tool options docker also available in canvas only mode on the canvas. You can show and hide both at any time, furthermore it offers a few small cosmetic options. The latest version is presented here:
It can be downloaded from here:
And here was the initial introduction of the plugin:
Another plugin that makes working in canvas only mode much more comfortable is KanvasBuddy. With KanvasBuddy you can display a menu on the canvas which gives you access to many functions, you can also customize it yourself and add or remove functions. You can find the topic here:
BUT with Krita 5 you can’t use the version linked in the first post, you have to download the version patched by @Halcyoen and linked in this post:
This screenshot shows how the redesign plugin puts Toolbox and Tool Options docker into the canvas, furthermore you see in the middle the free floating window of KanvasBuddy in a maximum configuration that has all inbuilt options enabled (even that can be extended manipulating a JSON-File if you have a little coding experience):
