I am a user of iPhone for past one year using my iPhone 4S my overall experience is very good where the phone is worth for the every penny you spend , many say the phone is over priced I got it from US and there it was around 650$ for unlocked when it adds 30% duty it becomes 45k in India which the actual price, ok Let me say the apps which will be useful for us. Waze: Since Apple maps lets down Waze is a wonderful navigation app.
Near me , Mercury , Voip apps like Libon, Tango , Bobsled free calling to any mobile or land phone in 5 countries (which was before free for the world) For more apps check out https://youtube.com/watch?v=Tr845iRC9gk
https://youtube.com/watch?v=FjPNHYm4qNc
To unlock the iPhones from US like AT&T without jailbreaking its possible with Gevey or R-Sim
check out the video herehttps://youtube.com/watch?v=lKBQteS8g5s