I have been using readera, xodo & kindle in my mobile for reading epub, mobi. Usually I read pdfs through default pdf Acrobat in the mobile. Also I'm using Ms edge for pdf, ice cream for epub ebooks in the windows machine.
But I want to know a reader which should like Kindle app which mean the platform free. It can be used in both mobile and desktop. Also need a cloud backup for that. Is there any e-reader application existing with my requirements?