Nielsen have found that, after the Android Market, Facebook is the most used app (How else will people download it?). This is among people aged 18 to 44, so therefore covers a large array of ages.
Who knows whats going on or why, but a fair few big name applications are going cheap on the Android Market. Right, when i say cheap i mean dirt cheap at 0.10p!! UK and US is of course 10 Cents!! The known list is below of what is available and boy is there some crackers. Swiftkey X, Minecraft, SoundHound and More!!