"My theory was that most people would be quite content with just three extra add-on applications - for Symbian OS, at least, in view of the wealth of apps that are built-into most S60 phones now (everything from image editing to podcatching to internet radio to mapping, it's all there out of the box, it seems). Other platforms have different needs and I'd estimate the number of third party apps needed to bring a Windows Mobile, Blackberry, Android or iPhone device up to the same functionality level to be around five or six for most people."