If you want to play airplane simulation and you want to really fly and enjoy flying then I still recommend you to buy the X-plane 12, because it is much closer to flying than the FS.
https://www.x-plane.com/
I don't known but you can use a Calibre https://calibre-ebook.com/ and convert PDF to EPUB on your PC. Its much better convert on PC because for convert you need lot of power.
I use a openboard + native library for flow typing. I was long time gboard user but open board is now best for me.
https://github.com/Helium314/openboard
If you want to play airplane simulation and you want to really fly and enjoy flying then I still recommend you to buy the X-plane 12, because it is much closer to flying than the FS. https://www.x-plane.com/