The optional Pro subscription is $US30 p/a (with differing prices in other regions).
There's also the free version of the app which includes ad blocking along with a 1 month free trial of the Pro version available in-app to see if it's useful for you before committing to a full year.
There's also the free version of the app which includes ad blocking along with a 1 month free trial of the Pro version available in-app to see if it's useful for you before committing to a full year.