I travel everywhere by public transport and have several pre-paid cards which not only bloat out my wallet, but cause an inconvenience when I keep having to take them out and put them back, getting on and off buses and trains. I have a flip case for my iPhone 5 which allows me to store a couple of cards and a few bank notes, but I don't really like flip cases. I wanted something that I could attach to the iPhone without changing the normal case.
There are a number of sticky sleeves which can be attached to an iPhone case and I picked the black neoprene Smart Wallet from Amazon (UK) which set me back £4.99. It comes in other colours and even a Union Jack design (for an extra £1.00).
The wallet sticks very securely onto the back of the iPhone and is stretchy enough to provide enough space to hold three plastic cards, a pair of railway tickets and a couple of banknotes. Just the job for when I'm travelling, and it means I can stick my wallet in my bag rather than leaving it to the mercy of pickpockets in busy London stations!
After two months of constant use, the Smart Wallet shows no sign of peeling off the phone and no obvious signs of wear and tear. A simple low cost solution that works well.