Font Size? Backups? Registration?

I've recently purchased Ninox from the app store, (I want to keep the database on my computer without cloud backup) and I'm slowly "finding my feet" but I have a couple of questions

1.  I havet been able to find answers for in the online info. 1. How to I globally change the font size in all fields? Ninox is obviously designed for people with better eyesight than mine.

2.  I cant find an option to switch off cloud backup.  Is it necessary to change any default backup?   

3.  I have not been asked to register my copy of the software.  Is the App Store purchase all that is requiired for registration?

Thank you.

James Matthews