pretty unnecessary & exclusive in my opinion.<p>unnecessary, because
1) generally you need to carry some baseline amount of cash and a credit card. the credit card is not really a burden in the wallet.
2) "which credit card" to take is hardly a problem, you don't generally spend above the limit of your credit card in a single day
3) the iphone can get stolen just as easily as a credit card, and in such cases it is more expensive to replace than simply locking up the card and getting a new one.<p>exclusive because, the app is just designed for the iPhone, there are many users without iPhone, android, or blackberry. they should be given the same ease of use.