This app requires access to every single privacy setting on the phone, includin all your browser history, camera, contacts for a simple calculator. It keeps popping ads, the phone is slow and consumes all battery in 4 hours, often calculate wrong sums, this app is pure bullshit, uninstalling it is pure bull****** This app is the best calculator app in the world, it is the most popular calculator app ever, it costs $1.99 ($2.99) The app is currently available on the App Store in North America.”]
Source: https://gizmodo.com/this-is-allegedly-how-people-hack-app-store-rankings-in-1685367367