Hey all, found this online and figured it was worth a share. http://asa.scitation.org/doi/full/10.1121/1.4865269 The SPLnFFT app had the best agreement, in unweighted SPLs, with a mean difference of 0.07 dB from the actual reference values. The SoundMeter app had the best agreement, in A-weighted sound levels, with a mean difference of −0.52 dBA from the reference values. For unweighted sound level measurements, NoiSee, SoundMeter, and SPLnFFT had mean differences within the ±2 dB of the reference measurement. For A-weighted sound level measurements, Noise Hunter, NoiSee, and SoundMeter had mean differences within ±2 dBA of the reference measurements. The agreement with the reference sound level measurements shows that these apps may be considered adequate (over our testing range) for certain occupational noise assessments. The evidence suggests that for A-weighted data, SoundMeter is the app best suited for occupational and general purpose noise measurements. In addition to having the smallest mean difference for the A-weighted data, SoundMeter had the narrowest distribution of differences, as shown by the box plot. The apps with differences outside the ±2 dB/2 dBA are considered not to be in good agreement with unweighted and A-weighted measurements.