Probably an offtopic for your offtopic, but:
I use my phone to read e-books:
- AMOLED screen (black color doesn't emit light).
- low level of brightness (so I can read in the night without "losing"
melatonin). Usually e-book reading app gives you this option.
- the PDF reading app must have reflowing of the text, so you can choose
the size and font you like.
- no blue colors (ie yellow "face" with a black background). Not sure
about its effect, but everywhere I read about blue filters. 8-)
Orgzly I use to capture ideas; and other tasks related with
auto-organization (GTD). Of course, the .org files are sync with my
computer.
For reading org-mode documents on mobile, I haven't found the perfect app.