[Spiffy]

The easiest and most practical suggestion is to emulate what's been done in the 3rd party firmwares. Coolreader updates and just as importantly BASIC file maintenance.

The ability to do very simple things like delete or move a file (on the 3rd party firmwares its done via holding the "1" button down and getting a pop-up "File tools" menu), without having to hook up to a PC every time, is more of a necessity than a luxury, I'd argue. Your devices are tailored to hold hundreds, if not thousands, of files, and have a battery designed to be used on its own for days or weeks at a time. So having to hunt down a PC simply to deal with basic file maintenance should be a no-no.

The current third party firmwares are only part way there, in fact. They allow deletion and moving between SD card and built in memory. What they SHOULD have instead (and what I hope a professional developer could implement officially) is a more traditional "cut and paste" system, where you can cut and paste a file between any desired directories (and of course, still have the "Delete" function).

One thing which would be HUGE (but even the third party guys haven't come near it) would be some kind of file search (again, its something you can currently do with a PC, but to have to find, power on and use a PC every time you want to find a book is... tragic). Since the readers don't have alphanumeric keyboards, admittedly the input for a file search will be a bit awkward, but the code to use the number keys to do alphanumeric input (like on old cellphones) is already out there in the Linux public domain, I believe, so it should be adaptable (I think something like its already inside Coolreader, for example).

Oh. Here's a real simple one (but very convenient). Add a "Favorites" feature. The same way there's a "Recent files" item on the top level of the file browsing, there's should be a "Favorites" item--which should be populated by a "Mark as Favorite" option in the same "File tools" menu as the Delete and other file options. As long as the File tools menu overall is being implemented, adding this Favorites functionality should be easy.

Also, one issue with the already existing "Recent files" area is the limitation to 8 items. Honestly? That limitation is just dumb. It should be expanded to four times that, using the page turning buttons to see older stuff.

And finally we should get a bit more information in the file descriptions. ePub files should contain metadata, I think, which should allow author names and titles to be elaborated instead of just spitting out the file names. This isn't a make it or break it, since most of us are careful with our file naming, but it would be helpful. I think fb2 files may already do this in your interface, but FAR more people use ePub these days.

Pie in the sky (and definitely last on this list) might be the ability to show book cover thumbnails in the file view. The only reason I even mention it is because it might involve the same kind of coding needed to read author names and titles from the files, so if those are implemented, the thumbnails might not be all that far behind.