let's first summerize your problems:
:arrow: On/Off button: solved
:arrow: I'm not responsible for the registration of any of the products of Aerosoft, you should wait for confirmation from Aerosoft itself.
:arrow: I don't really get the idea... You've clicked the MODE button and you don't get any information on the calculator? Please upload here a screenshot of the calculator after you've clicked the MODE button.
The problem might just be that the correct font isn't installed. If so, i'll be able to guide you through the installation of that font.
:arrow: Did y