(Joplin's dev here) Can confirm that Joplin can embed images - you can copy and paste an image directly by pressing Ctrl+V in a note, or attach them. It's also possible to attach any other file, PDF, etc. and open it in an external viewer on mobile or desktop.

Evernote import is also supported and as far as I can tell works well for many users. If you find any glitch or issue though, feedback is welcome.

The app is still under development with, at the moment, a focus on bug fixing and improving the desktop and mobile usability.