I've been working on a stand-alone software defined radio (SDR) application for Mac OS on-and-off for a few months, and I think it's good enough now to encourage people to test it and provide feedback. Though it's possible, of course, to do everything my app does in GNU Radio, it's much more convenient to have a dedicated app. Especially because this app uses a lot less CPU thanGNU Radio.
This video shows the basic operation of the user interface:
And this one shows an 'inside peek' at what happens to the signal inside of the application. In normal usage, the waterfall display won't do this, but it's an interesting effect:
There are still many, many bugs, but it should be enough to play around with.I've been able to listen to broadcast FM radio for some time using the app.There is no squelch control, that's on the list of things to add. Also, it's possible to get audio buffer under runs. It's likely caused by slight differences in the clock rate of the rtl-sdr dongle and the audio device that you're using.
If you notice any bugs, or have specific issues that you would like addressed, please create an issue on the github page. Also, if you are able to contribute, please let me know. I'm obviously in need of some GUI assistance!
One word of advice, don't try to change the modulation type using the drop-down menu, it doesn't work! :)
Again, code is available at github, as is an application binary.