My feedback is that if the subscription to have more features in Opal was cheaper annually, weekly, and even had a monthly subscription there would be more users and more people would use Opal consistenly.
I think 9.99$ for a week is very expensive and majority of people don’t have that amount to just give out; on the other part, 99$ a year seems reasonable, but then most people are in a position where they can’t drop that amount of money at once or they don’t know if they’ll stick with the app to pay a hundred dollars that quick.
This is why I think there should be a third and middle option for a monthly subscription that is accesible for most users.
Finally, I believe that if in the free version one could have more than one session saved you could retain more users and then have them be premium users.
Hopefully the Opal team can take into consideration the points that were made here.