I said that I did not find Pitch Primer very useful ...
In my earlier article Learn to Sing In-Tune with iPhone Apps, I mentioned Pitch Primer as being 'worthy of mention', but then stated that I did not find it useful, partly because the view of pitch is not at all damped.
Actually, now I find Pitch Primer to be quite good.
As it happens, as my in-tune singing practice has progressed, and I have become more able to consistently move from one reasonably correct pitch value to another reasonably correct pitch value, I have found Pitch Primer to be a more useful practice app.
Indeed it is now my main practice app, for singing, and has replaced the previously preferred Cleartune.
Pitch Primer does show a very undamped view (as you can see in the picture above), but that is because it is just showing the actual pitch being sung.
What I have found, is that although a very undamped needle display is not so useful, it is possible to learn to practice against an undamped trace. Also, the best singing voice is often a vibrato, not a perfectly flat pitch level (and holding a perfectly flat pitch level may be more of a strain on the vocal chords than a vibrato), and the trace displayed by Pitch Primer clearly shows any vibrato, and at the same time you can still judge if the average pitch is in the right place.
How Pitch Primer could be even better, as a singing practice app
I now find Pitch Primer very useful as a singing practice app, but it could be made even better.
Here are some issues I have found, which represent opportunities for the authors of Pitch Primer (hopefully they are reading this) to make their app the best singing practice app ever:
Initial Mode, and the "Standby" button
The initial state of Pitch Primer, when you start the app, is not showing the current pitch level. Other tuning apps go straight into showing you the pitch level (because they are tuning apps, so it would be pointless to do otherwise).
The first thing I have to do, every time I start Pitch Primer, is press the "Standby" button. Or, I start singing, nothing happens, I think to myself "Why is nothing happening, oh, that's right, I have to press the 'Standby' button first", and then I press the "Standby" button. So, please, skip the "Standby" button, and just go straight into the mode of showing the user the current pitch level.
Settings menu hard to use, and not always active
The "SETTINGS" menu is small and hard to activate consistently. And it only works when in the state where the app is not showing the current pitch level.
App settings in the iPhone Settings app
Most of the app settings are not in the app itself, but in the iPhone Settings app. Apart from the microphone permission setting (which presumably has to be there, because it's a permission), everything else should be in the app itself.
The current 'workflow' for changing settings is: go to iPhone main screen, open Settings app, scroll down to find 'Pitch Primer', find setting to change it, change the setting, go back to main screen, go back to Pitch Primer, and, finally, see what effect your change had on the app.
No separate iPad version
There is no hi-res version of the app for the iPad. You can use the existing app on the iPad, but it's a fuzzy pixellated version of what you see on the iPhone.
If there was an iPad version (or if Pitch Primer was more 'screen size aware') it could have the option of showing a longer historical trace.
An additional optional damped trace would be nice
Given that Pitch Primer displays a very undamped version of the pitch trace, it would be nice if there was an option to show an additional damped version of the trace (with perhaps an adjustable level of damping). That way, it would be easier to judge if the mean pitch level of a note sung with vibrato was correctly hitting the target note.
Doesn't work well for whistling
Pitch Primer does not track whistling very well. It does track the pitch level, but then it may suddenly jump to a completely different pitch level, and almost instantly jump back again to where you were, which combined with Pitch Primer's zoom-in and zoom-out feature, makes it difficult to track the pitch against the target note. (Cleartune does not have this problem, so if want to practice whistling in tune, Cleartune remains the currently preferred choice.)
What is the exact length of the current trace?
The trace seems to show about 2 seconds of trace, but I can't find any documentation that specifically says so. It would be very useful to know the precise value. For example, an ideal rate of vibrato is 5 oscillations per second, so it would be useful to know that this corresponds to 10 oscillations visible in the current trace.
The System Time display is suppressed
Most iPhone apps show the current time and the rest of the standard iPhone banner at the top of the screen. Pitch Primer does not show this – perhaps the authors thought it was an unnecessary distraction that users could do without.
However, consider a scenario where you have a chance to practice for 10 minutes before you have to go somewhere else. In that scenario, not having the system clock display is actually annoying. So, it would be nice to at least have the option of the showing the system banner.