I culled the following list from XDA, Phandroid and Nexus 7/Nexus 10 Forums. Some folks have gotten keyboards to work on the Nexus 4 and 10 but I haven't seen any reports of success with the Nexus 7 2012 or 2013 running 4.3:
I'm using a Zagg, and it'll pair. I can enter the code. The Nexus seems to recognize what it is, but once it's all set up the keyboard is completely non-functional. It wont move around the home screens and it wont input in a text editor.
Perixx PERIBOARD-806, Bluetooth ALU Folding Keyboard
It pairs with difficulty and shows connected but the soft keyboard still appears and it will not type.
Apple Bluetooth Keyboard
Is anyone else having issues with their bluetooth keyboard when paired with the Nexus 7? I have an Apple Bluetooth keyboard and it repeats characters, and inserts the spaces out of order.
My Apple A1255 keyboard pairs but no longer connects in 4.3 on my Nexus 7 (2012). Works on my Nexus 4 with 4.3 and worked on 4.2.2 no problems.
Spider Bluetooth Keyboard
I recently purchased a Spider bluetooth keyboard and I can get it to pair with my Nexus 7 (which recently updated to 4.3). The tablet recognizes it, and I type in the numerical code and press enter on the keyboard and the Nexus 7 responds. However, I can't get it to work in any other app after it pairs (I've tried unpairing it, turning it off/on, restarting the tablet, etc).
Unknown Bluetooth Keyboard
I have a Bluetooth Keyboard and he works perfectly if im using the 4.2.2. Now only the letters work, no Space, no enter, no backspace and nothing more... Anyone have this problem too? (Sorry for my poor English)
I got the same problem with my bluetooth keyboard and other issue with the ShareKM app The cursor is invisible.
Kensington Bluetooth Keyboard
I have a Kensington UK bluetooth keyboard and although it shows as connected and typing the numbers to pair it worked, I get no input at all...
GYMLE Bluetooth Keyboard
I have a GMYLE keyboard and it will connect but no key will register on screen
Has anyone gotten any Bluetooth Keyboard to work with the Nexus 7?
Does anyone know how to report this to Google?