I've been using this app for years. A couple months I needed to use forwarding, which is a Pro feature.

I thought I already bought it years ago, but the app asked me to pay so I bought it again. It instantly locked me out of the whole app. Later I checked and I had bought pro already in 2014 (for 5€, and I paid 30€ this time). Absolutely no answer to my emails.

Thanks for the instructions.