I don't know if it is a problem all of us have with coolreader on the 902, but there does not seem to be a 'standard' exit option..
The consequence of this is that (on my reader with 2.0.4 EU) Coolreader forgets what last opened book was, and on what page. Shutting down the reader like what i do with FBReader/FBReader180 results in starting up with the main menu of the reader and Coolreader with no idea what book was open on what page whatsoever

I fixed it (sort of) by adding a 'quit' option to the keymaps.ini file in /system/share/crengine/keymaps/
Under [main] i added:
KEY_MENU = MCMD_QUIT
The key with the icon of the open book now exits the coolreader app, and subsequently remembers the last open page