I have been trying to get to like this application since it "grew up" and became shareware.
Unfortunately, the income from sales doesn't appear to be used for development. Presto is slow and unresponsive and cannot match the font you have chosen for a particular document. It is restricted to the font that is selected in preferences.
Despite the developer's claims that it is Snow Leopard compatible, it has failed to work for me since updating and now doesn't launch!
The response to my request for support was unhelpful to say the least.
I really don't like to criticize applications but this one has wasted so much of my time and a little of my money.
Now I'm going to use AppZapper to remove all traces of this useless thing from my Mac and put this "developer" on my blacklist.