I'm very out of date when it comes to things that are cellular/mobile. There is a vague reference to an "in-app product". What does that mean? I haven't used the software yet, neither trial or pay versions.
I think you are referring to the app listings on Google Play. Any app that offers in-app purchase has "In-app product" label. Funamo comes with free two-day evaluation. After two days, the protection will be turned off. If you would like to continue to use Funamo, you can purchase a license through either in-app purchase or on Funamo website at https://funamo.com/buydirect