Out of all the old apple devices I have to choose from none meet the requirements for using Marvin.

I had to resort to using another app that works with Calibre but its not my favorite app. Mega reader is the name (I think).
In my perfect world Calibre and Moon Reader + will make an app for apple devices.
Most of the time I read with my Kindle but at times I need to use my IPhone.
oh also do I want to save the cover and metadata separately ?