Hi Petr,
I know at least five ways of contacting me exposed through either plugin homepage or page of free version.
I don't understand what do you mean by half-working.
Currently the service is free for all. I provide only minimal support. Though you may pay for it through
http://msgnotes.alehro00.com/perm1/subscribe.html.
There are some bugs in site's user add procedure. If you need to add users please let me know.
Kind regards,
Alex
Alex