www.chinaphonearena.com

Hi, just wondered if the v3 can be used to back up my nfc gym card and use the phone instead of the card?

Probably not,

First off the kernel needs to support NFC host emulation for the NFC chip.
Also NFC host emulation is to be supported from android 4.4 and up, but that doesn't necessarily have to be a problem.

For now you can try two apps and see for yourself whether they work or not:
[Only registered and activated users can see links Click here to register] (download via [Only registered and activated users can see links Click here to register].)
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