For use with the app "LeafSpyPro" I purchased an IKKEGOL Vgate iCar3 mini OBDII WiFi scanner tool for about $35 on Amazon. This is a tiny scanner that I just leave in place all the time. It shuts off about 30 minutes after the vehicle does so no residual battery drain. If it matters to you, the device comes in 5 colors.
So far (several weeks) it has worked well, pairing quickly to my iPhone without manual intervention. The documentation that came with the unit offers a free software tool but with "LeafSpyPro" so specifically tuned to my LEAF I haven't bothered to download the free tool.
2012 SL Super Black
Registered to order: April 20, 2010
Ordered: December 6, 2011
11,900 miles, 10 bars showing, 75% SOH, 49.80 Ahr