I am going to do some sound frequency measurement. I have found the 3rd party library which enables performing Fast Fourier transform(FFT). Can I use them in Windows Phone 7.5(7.1SDK) application so it will not be rejected by Microsoft in the apphub?(the bold part of the question is more important)
Found libraries:
You can use pure managed libraries without any issues (assuming they run in a low-trusted environment and don’t make any external API calls, so a math library should be okay).
Others, like AForge, will not work, because it’s a native library (and the ability to run native code on WP7.1 is not guaranteed). Things are different on WP8, however.
The Exocortex DSP library looks like it might work as well.