I use it on my iPhone 6 to quickly pick out resonant notes in my PA system when setting up for a gig, and this app works great for that. The mics on the iPhones and iPads are not calibrated reference microphones, so the app is not accurate for ringing out a room for a perfectly flat response, but for this price I'm very happy. Works great on my iPhone 6, but the screen flickers constantly on my third gen iPad since the latest update. The app is still useable though; the flicker is merely annoying.

Ok, Im a professional Videographer but I am not a sound man. sometimes I have to be one. I am absolutely giddy and blown away how a $4.99 app on my iphone 6S plus can quickly tell me what frequency an electrical transformer or fluorescent light fixture ballast room hum or an AC air vent noise is so i know what frequency to filter out in post to remove it from my video soundtrack. Not sure if there is a feature to save the pause of the screen like a screen capture to photos or possibly email it to myself so when i get back to the edit suite from location, i can reference the image to work with. That would be a very sweet addition to the next upgrade! This app is fantastic regardless of missing that enhancement..... 5 thumbs up! 👍🏻👍🏻👍🏻👍🏻👍🏻

I must say I am more than disappointed with the latest update, as it does away with two of the things that made it unique: (1) the ability to monitor up to 1/12th of an octave (aka 12 musical semitones per octave. After all isn't this the namesake of the app!?) and on a related note (2) touching the graph no longer provides the quick frequency to pitch readout (aka musical letter name). I can't understand why you would use the update to remove essential features that made your product unique? I used this daily in my professional music mastering studio previously. Also, as a professor at a music technology university I used to recommend that all of my students purchase this app for ear training purposes. We are now experimenting with a replacement, while sorely missing the old Octave app we all used to rave about : (

I love this app! It definitely does the job! It is practical without being complicated. Reminds me of the old hand held analyzers we had years ago, but it's much better! I like that I can switch from octave to 1/3 to 1/6, also that I can switch from bars to line graph, change the speed, and choose the type of peak indicator I want. And pause it while I make adjustments to my equipment!