More of a scratching my own itch kind of thing. Has over 30k registered users but I don't even get enough to pay for my server! LOL.. So meh.. doesn't matter...
Looks like you have a paid plan now, good for you! But $29.99/yr seems waaay to low. I would suggest making that the "personal use" tier and adding a third more expensive tier for businesses.
Because I launched it as a free app... I didn't have any confidence in it and at that moment, there was no way for me to accept payments internationally.
I recently revamped the app, added features like real-time collaboration, chrome-app integration etc., and put that under a subscription. But have no time to market or spread the word around. Moreover, I'm not sure how to get free users to convert over to paid so, that's why exactly why I think this site is an apt example for this topic.. haha!
Just an idea.. Try the wikipedia model maybe and ask for some donations if you've been using the app. I did this with an old product and it was helpful.