Great app I will give a star for each point implemented: 1. Subtracting of pre recorded spectrum(e.g. noise) 2. Lower sampling frequencies(e.g. 4kHz, 2kHz) 3. Saving of spectrogram in text Or higher resolution image with time marks Other than that this app is much more accurate than tons of others I tested.

Don't buy the full app stick with the free one I thought the free app was good. I kicked myself for forking out for the full version. Random signals and differences between devices asked for help was told to calibrate? Sent images of faulty traces but no reply since then. In short for me poor support, over priced app with very little extra for paying full price. Use the free one and stay happy.

Logarithmic scale is off The logarithmic scale feature which I paid good money for is not accurate. Middle C which appears a perfect 262 hz in the linear version appears to be 200hz or so. Also you cannot rescale to limit the plot to a particular octave. I want this app to be able to tell me which notes are being played in a piano chord, but I cannot trust the scaling - please fix this before I up my rating. It would also be a great help if you could rescale in musical notes, so that you can clearly see which notes are being played

Unfinished feel. Great idea mediocre implementation. Set an option you phone doesn't support and it'll not work... Restart the program before changing it back and you get an "unsupported configuration" error and an instant quit, making it then unusable.

The basics are great, range zooming very bad. It kind of works, but in an unpredictable way...you have to randomly mash your finger on the amplitude and frequency scales until something useful hopefully appears. 5 star app with range scaling fixed, particularly with numerical input. FFT works great, very fluid.

Free version is just as good. I loved the free version, but the pro version is not worth what I paid, and there is no refund. If it had more options for LOWERING the sample frequency not just raising it, I would give it four or five starts. Not enough options to make it worth the money. Stick with the free version.

Really needs X-axis labels…   This app really needs time labels along the X axis.   Other than that, I am quite impressed.  My background in acoustical analysis would make this of interest to me, but I think even those without such a background would have to find this very cool.  I have a memory, from more than a quarter century ago, of being shown a waterfall plot, and hearing the sound that was represented, and having a light go on in my head about the relationship between what I was seeing and what I was hearing.  Back then, it took the better part of an hour for a pen plotter to draw the waterfall plot that I was shown.  I can imagine people today, watching this app on their phones in realtime, and having the same epiphany that I had back then.   About twenty years ago, I wrote a program like this to run on an MS-DOS-based computer, in realtime.  Back then, it took a specialized digital signal processor to handle doing the FFTs fast enough to make this possible.  Isn't it amazing how far the technology has advanced, since then, that this can now be done in a small, common, handheld device.

Useful technical app I use this program on my phone often to analyze sounds and visualize sounds that are below audibility. Consistently works great! Now I have started using it on my tablet. Never any problems.

The benefits of the paid version over the free version aren't worth the cost. The app works well, but for paying what I did for this app, there's a couple features I'd like to see that are missing: -Screen rotation (I apparently like to put my tablet opposite how they expect, and their app refuses to rotate/flip from its default orientation) -More frequency selection, or zoom (as a person with a low voice, all of the frequencies I'm interested in seeing are typically crammed into the bottom third of the screen, even with it set to show those as much as possible) -Ability to record a long sequence of audio, play it back, pan through the output, save (and not just a screenshot, but actual audio), and maybe even view spectrums for audio files. Basically, more than just 'what is coming in the mic this very second'

Very pretty, but lacks time axis Surely showing the time axis should be optional? It might be fixed by the sampling frequency but that's no use to a third party looking at the data wanting to know the most basic attribute of the data. Not "PRO" until that's added.

Too many bugs for the price App has way to many bugs for the price and it could also use some sort of users manual. The free version is worth the price

Great tool Helped me identify the charger in my room emitting a high pitch electrical whine. The price of the app was reasonable for a good nights sleep :-)

Best on market On ASUS TF700 tablet only shows half the scale. If set to 16kHz will only show up to 8kHz on graph. Please fix. Does this on all graph settings. Thanks!

Great quick diagnostic tool Ive used this app in a professional engineering setting multiple times for in the moment decisions. There are small unit labeling bugs but any good engineer double checks for these mistakes.

Nice but needs more features. Great app, to 5* I'm missing: * Mel or/and Bark frequency spacing (frequencies relevant for human hearing) * X axis labels * FFT sample size option * full screen mode (hide buttons and optionally status bar) These should really not miss in a PRO app.

Not sure if right The scale on the side doesn't show the right numbers. For example the 24 kHz sampling shows 10.5 as the highest. And 8 kHz shows 3.5 as the highest. Should be closer to 21 and 7 respectively.

Errors. No response from developer. Money lost. Don't let it happen to you.

'grebe52 using Galaxy S2 Works well with Android 4 on Galaxy GT-19100. I've been working on birdsong, and this application produces a decent and useful image of the analysis of the song, say, of a Blackbird (European), detecting frequencies well-beyond my (ageing) ears. It will also detect Bat echo-location signals. As an retired physicist I find this device incredible, when I recollect the amount of kit such as the CROs, mics, amplifiers, which was needed to do such an analysis years ago. I can sit in the garden and 'watch' the birdsong, with one small smartphone! It has also been useful in looking at the overtones emanating from a Tibetan Singing Bowl, and likewise by Mongolian Throat Singers. The fun is endless! A labelled y-axis would be a refinement. Nevertheless, an excellent application.

Could be useful with some updates 24k causes the audio on Samsung GSIII to fail. It could also benefit from a calibration option, like your frequency analyzer app. Also, a change in orientation option would be great to see a wider view of the frequency range, to help isolate problem frequencies. And saved settings are a must!

Decent It's a fun program but I don't feel it was worth the money as it does not save your settings. This is a basic feature that should be added.

Is there a developer in the house? For what this app is, the standard bearing app of its kind, it needs some very basic work. More scaling options? Faster scrolling, I.e. wider spectrograms - just literally stretched out would be great.

4*: Missing zoom, time scale (15s?), sound capture, playback, and setting memory features puts this awesome app just short of 5*. Pretty basic features...

Very useful. Used this to pin down a high frequency noise coming from a couple of speakers. Works as advertised.

Nice when it works Crashes on my S3 whenever I try to change the sampling frequency. Otherwise a nice enough app.

Needs to go lower I bought this intending to use it to detect feedback frequencies while mixing monitors. It seems accurate, but will not detect anything under 1k, which makes it useless for low frequency feedback. Will give 5 star when this is addressed.

Need lower frequency I need to view frequencies from 200hz and below, can the lowest frequency be lowered from 8000 down under 1000 or lower in the next update please?

S3 problem Every time I use the 24, 000 hz setting my phone craps out and have to restart it. Need update to fix it

Everything I needed for noise reduction Great app! As a design engineer this really helps to understand resonances and related issues without a real sound lab.

One short coming I was hoping for more versatility when selecting the different variables and such. I can't quite investigate a sound in the detail that I would like.

Your app is good and you should feel good Perfect. Very smooth and all the features I want in a spectrograph.

Nice app Would be better if it had more settings. I like the visual layout of this app more than others, but tha lack of settings like window size makes it less usful.

Update is even better Galaxy S1 now supports 32kHz sample rate. Peak frequency value is great!

Would be nice to send screen prints and zoom into lower frequencies

Loved this 2 years ago and love it still. Just don't get why I need to pay for pro all over again...

Input? Its a good app. Ut could you give us the choice of input between the mic or reading from the audio player

Cool! Does one thing and does it very well! (Just used it to find the frequency I sing at, and the frequency I whistle at.)

Ads? Pop up ads in a paided app?

Neat Great app! Just what i was looking for. Is it possible to utilise the headphone jack for a mic in future versions?

Great tool Suggestion: Need button to make the screen clear. Overall, it's perfectly doing their job.

Display is good The display for frequency content is very good. I hope developer provide more standard sampling frequency choices.