If like me you're using a qwerty keyboard, but sometimes you have to use special characters like é å or exposants, you can be easily discourage to use vim as a note taking app; that's where vimvimvim comes to the rescue.
TODO
Plug 'weshguillaume/vimvimvim'
In insert mode, press eee to get a list of possible accentuations for the letter e. A pane then opens itself. If you want the accents of the a letter, simply type a in this pane, and so on
In order to add your own character you can either make a pull request or edit the global dictionnary g:vimvimvim_dictionary:
g:vimvimvim_dictionary.c = ['ç', 'c']
imap ccc <esc>:call vimvimvim#open('c')<enter>