Checking in to say it works.

Had to reboot after first install before libusb would work properly. rtl_fm worked but I never got any audio out of aplay. Might be a root user issue, dunno. Ran at about 80% CPU usage.

Had some trouble with some libboost deps for gqrx, couldn't find the newest version with apt-get so I just grabbed them straight off the repos. The UI/FFT runs very smoothly if you disable any and all demodulation. I managed to run that for maybe an hour before my battery went completely flat. The screen did turn off so it might only be half an hour of good running time. I did have to run it as root to get it to use the rtl dongle properly.

gqrx did peg CPU usage at 100% the whole time but the phone was surprisingly responsive the whole time. The main interface isn't too bad either on the N900 (If you keep samples <1.024MSps). I'd say it's one of the better applications out there for mobile SDR FFT viewing (better than SDR Touch or ghsphr or whatever it is).

Here's a screenshot for good measure:


edit: Sound works fine. Silent mode was on.