I've been testing Cerberus for a week now. Just bought the full version this morning. Only cost $3.70, which is very reasonable considering you can add up to 5 devices at no additional charge. I'm also running it on my Gnex as well. Great web interface lets you track all your devices, take photos, audio, video and remotely lock and wipe your devices. SMS to phone also activates actions.
Note: Nexus 7 will have volume issues with the current market release. You won't be able to use your volume rocker to adjust volume after you install it. Just send a trouble email to the developer and they will send you a beta version that fixes the issue (sent mine within 15 minutes). The dev is great with replies too...
Just my 2 cents...