How about using kickstarter to fund Joplin?
Joplin has a lot of potential to become something very good so I think funding Joplin would be a good idea.
The developer can get extra funds , hire other developers to help him and also devote some more time on Joplin.
I have funded before a couple of weeks
https://www.kickstarter.com/projects/jik/rewritten-add-ons-for-mozilla-thunderbirds-next-release/description
so why not Joplin…
I guess that would be useful to fund certain things that we can’t easily do ourselves.
Examples are things like hiring a designer to refresh the UI design; hiring a security firm to do a security audit; getting someone to develop a native mobile module for decryption or sync, etc. Basically something that can be easily scopped and for which we can get a quote in advance.
I am a proponent of this and would love to contribute to a fund since I cannot otherwise contribute my brain 
+1
Would contribute