There are a lot of different AV tool kit applications developed for the Android and Apple markets that address just about every A/V need. From lighting to audio, and everything in between, you can guess they have an app for that. However, there are also a lot of apps that are fine-tuned for a specific purpose. Whether you are measuring a throw distance for a specific brand of projectors or trying to measure the decibel output of a newly staged speaker system, purpose-specific apps are out there and most of them are very accurate.
The following slide show contains thirteen Android and Apple audio apps for audio spectrum analysis. These apps cover a range of audio measurements, some measure RTA and others FFT, they also range in data presentation some display 2-D graphs, both logarithmic and linear, and others display 3-D content with waterfall graphs. Regardless of the differences, similarities or unique qualities of each of these apps, they are designed with the A/V professional in mind.