On the "fun toys" front, check out Edward of Effingham's Heraldic Avatars. Nothing fancy, just your device, nicely rendered in pixels for a very reasonable price. I may have to invest in one of these.
Recent eBooks from Project Gutenberg:
Dewey Decimal Classification (from the 1976 reprint of the 1876 original). Tables. Lots and lots of tables. But it's tables about books! (Did you know that category 678 is just "Cotton"? Some classifications made a lot more sense a century ago.)
Selected English Letters (XV - XIX Centuries). Mostly out of period, but a modest number from the 16th and 17th centuries that are potentially interesting.
Ravenna, A Study (1913). Mostly *pre*-period, but has several chapters on the Middle Ages and Renaissance. Probably of interest only to I Sebastiani...