JohnHair.com

This used to be one of the best calendar app. Since the new upgrade, it does not even open !
So I can’t use it anymore. Guess I paid for nothing.
Developer should at least warn about which system accept their app.

Hi Dean,
Thank you for reaching out on this issue. Some good news for you though, you can delete the app and re-install. Don't worry, you won't lose your events as they are stored within the internal iOS calendar, and myCal PRO simply reads and writes to those.
I have also added this information to the review you posted.
Also, if the app wasn't compatible with a specific hardware configuration, the AppStore wouldn't even allow you to install it.

Regards
John