And what is exactly your point? The specific app is not intended to be a part of the OS interface. It is using a more immersed, recreational interface, which makes it fun to use. (Have a look on the review here to see what I mean:
http://www.inews24hs.com/2011/03/15/led-machines-–-led-flashlight-for-iphone-4-review/ ) Users enjoy the animations and sound effects. They are using it for the whole experience, not just for the usability of it.
On the other hand, OS interfaces are belonging to a different category. And although there is a trend to make the native OS apps more immersive (take as an example the new iCal. It uses an interface that tries to emulate a real object, a real leather Calendar), users could have given the option to switch between a more abstract UI style. The main reason of using native OS apps (such as ical, mail, etc) is more task centred rather than experience oriented. The ideal would be not using any interface at all and just have a personal assistant do all the hard work for us accepting voice commands. Hopefully we are not far away from something like that though…
It is interesting to notice that there are two different trends for the interface design criteria of the OS apps. Two different schools. One is the school of immersive interface, such as iCal, garageBand for iPad, iMovie for the iPhone with all the eye candy on the movie selection menu. The other is the minimalistic approach: the new Mail interface, the iPhoto, e.t.c. It is as there are two different interface design teams working in parallel, doing their experiments on UI usability, each following a different direction.
A bit out of topic though!! Lets get back to the slider conversation!!