Universal reader of electronic books from the monitor and from mobile devices - a revised version

Good afternoon, dear colleagues! Earlier, in this post , I introduced the enreader.com service. I received many useful reviews and suggestions, for which many thanks. I propose to discuss the improved and augmented version of the universal e-book reader.

What's new:

1. Earned in Opera Mini. It looks a little different than on devices and on Android, but everything works correctly.
2. Now you can read a book on Amazon Kindle using the built-in browser.
3. Added buffer size setting. Now you can upload up to 400,000 characters, which is enough to read without a network in a transatlantic flight.
4. Added the ability to login with an existing account on Facebook or Twitter
5. Added a button to hide the menu when reading from the monitor
6. Added download PDF files as images, which allows you to save formatting and graphics inside. Actual for all scientific works with formulas and graphs. It is better to load books for reading as text, it takes up much less space. Traffic while reading eats at times less.
7. Added a demo book. Now you can see what's inside, without creating an account.
8. Simplified menu
9. Added sorting books by last open time
10. Fixed a bunch of bugs. It works better than before. But probably still something left, I will be grateful for the tip.

In the plans

1. Support formats mobi, djvu - what else to add?
2. Add a view mode with two pages on the screen (like an open book) for monitors and tablets
3. Screw the base of gutenberg.org so that the book can be searched directly on our website and downloaded with one button.
4. Apparently all the same we will make "friends" with the ability to "give to read" the book
5. Add a recommendation service - we will show who reads what, who likes what (if the user wants to show it)

Very interesting your opinion. What to improve? What to add? What to remove?
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Thanks in advance for your criticism, tips and suggestions!