Android

In the mobile sphere and tablet sphere Android is king. Not because it is better but because it has the biggest market share and it has the biggest number of apps for its users. I have no personal experience of Apple so I really can't comment on them. But I can compare Android to Windows Phone or shortened WP. And it's really quantity over quality.

First of all have you ever tried writing a long text on Android? Or just a sentence? The text on the screen seem to be one word behind your fingers on the virtual keyboard. And I'm a slow writer, And speaking of the virtual keyboard. On a tablet you can usually hit the right "key". However try a Samsung Galaxy S3 Mini and you'll be writing everything twice, at least.

And then there are virtual books. I know good writing costs but e-books available for the Android platform usually all cost something. And finding an app that can use you Google Drive or OneDrive a e-book source is difficult. Have you found one? I haven't.

Using a browser of any kind on a Android system. Well it helps if you got other things to do at the same timer

The only compliant I got against WP is that they should have entered the tablet market earlier and their tablet(s) are too expensive. A phone screen is still small. And the lack of apps for WP. Well  that's not really a compliant. Sometimes quality is better than quantity.