Not Supported

Hello,

I'm currently running Android version 13 and this app states its not supported, but only for older versions than my own. This is confusing to me as the website discusses numerous updates/upgrades as being the likely cause of some Adobe apps not being supported. Yet there doesn't seem to be statements regarding these apps not being able to be used due to the apps themselves as being outdated. What does one do in this predicament upon needing to obtain ebooks for my college courses? 

Thank you, 

Michelle