Just a small comment, as I don't know if you're planning to wrap up or keep maintaining the product...

I can't find the pricing of the product on the site, I only find that I get '10 free credits', but I don't know how much a credit is and what can I do with it.

Home page says it's one credit per diagram, but then the docs say it's a certain amount of credits per modification (that could be correct or not, I guess...)

I usually skip if I can't find the price, but it could also happen that people create the trial account, spends quickly the credits, then they find the price and it doesn't fit them. Of course, there's always people coming just for the free credits.

I don't know if this is helpful to you or not, but I hope so :)