Ads ruin experience - even after PAID FOR UPGRADE

I wanted a regular old calculator with no ads. I used the free version, and it was constantly interrupted by ads. I paid for the upgrade - STILL has pop up ads. And I’ve seen multiple reviews say the same thing.

I am a very generous reviewer, this may be the first 1 star review I’ve ever given. But a simple calculator that you can’t concentrate while using because of pop up ads defeats the point and ruins your work.

LewisFilm about Calculator Pro+ for iPad., v5.1