CustomArt Harmony 8.2
FFT Plot
Spectrum Analyzer iOS app
Oh man, you read my mind! Been also thinking about getting the 8.2. By the things are now, I probably won't be able to get the 6R anymore...
Just a comparison with Piotr's own measurements with the IEC-60318-4:
Not pinpoint accurate, but long as you're comparing IMM-06 measurements with other IMM-06 measurements, there shouldn't be any issue. Even moreso when the database is further filled up.
Thanks for the measurements Nick! Will be updating the front post.