I agreed to prepaid 1 month to use their pdf converter. After that they still charged my credit card for a second month without my authorization.
In their website they have an option to cancel membership but that option doesn't work, you can't cancel anything there and they still charge you with your credit card number. I went to the trouble of canceling my credit card number and reissue a new one. Beware that this company is trying to scam money from users.