No it doesn't work under iOS6. It's only under pre-iOS6 that it delivers >30 fps video.
BTW, I don't recommend it even for iOS 5.x users. Use SloPro instead - it consistently delivers 60 fps on the 4S, unlike Better Camcorder, which tops at around 35 fps.
(More info on all these questions:
https://forums.macrumors.com/threads/1489146/ )
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Dunno why they crippled it. Probably because the 5S will support 60 fps and they needed to cripple older but 60 fps-capable models (4s/5) not to shoot at 60 fps? Well, Apple is pretty much known for intentionally crippling their old models:
- removing antialiasing of the iPhone 2x mode from iPad 1/2 in iOS 5 and lying antialiasing in the previous versions were a "bug"
- making even two-year-old hardware like the 2nd gen iPod touch (sold, as a recent device, up to Sept/2010) unable to run any new app after Sep/2012 by forcing the deployment target to be 4.3 as a minimum
- making the iPhone 3G deliberately slow on 4.x. (It was all deliberate. They haven't done the same to the 2nd gen iPod touch, which has almost the same hardware. This is why the latter is orders of magnitude faster than the 3G, both running on 4.2.1 - unlike in the pre-iOS4 times.)
etc.
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720p is further halved - that is, the effective (vertical) resolution is 360 line pairs. Let me copy the relevant part of my dedicated article, which shows all this:
Recording video at more than 30 frames per second (fps)
Unfortunately, while it is possible to record more than 30 fps, the vertical resolution will always be halved (and, if you use the binned mode, also the horizontal), independent of the actual resolution used. This is the case with both directly editing
/System/Library/PrivateFrameworks/ MediaToolbox.framework/N94/ AVCaptureSession.plist and using the third-party apps(currently) capable of recording at more than 30 fps:
Better Camcorder and
SloPro.
It seems the system automatically switches to line doubling mode when any application attempts to record at any higher framerate than 30 fps. Yes, even recording at 31 fps will trigger this nasty behaviour.
This means you really don't want to record at high frame rates unless you really don't mind the reduced resolution.
Two examples at vastly different resolutions of the effects of the halved resolution (I've annotated the Nyquist threshold with a red line. An ideal camera should render an image very close to these thresholds in which the number of both the horizontal and vertical lines can still be counted. If they can't or are presented as fewer lines, aliasing already occurs where it shouldn't do.):
[clipped images and text]
