I was a little upset to find out that you needed a sperate back to charge wirelessly with the s4 and the Samsung back adds bulk, meaning my cases won't fit. I decided to get this:
http://item.mobileweb.ebay.com/viewi...d=261216364963 - it's inexpensive and is a Metrans! They go for much more money elsewhere. It works great with my nexus qi charger. Nfc works for me, so it should work for anyone. It doesn't add hardly any bulge at all. You cannot see a bulge in my phone if you aren't looking for it. It comes with 2 sided tape to stick it to the battery but I took it off and attached it to my aftermarket carbon fiber battery cover so I can switch batteries with ease. It works great! Make sure you select the s4 when you purchase. Delivery is about a week and a half.