The TPMS in each wheel talk to the Leaf not the Android or iOS device. The wheels talk to the Leaf and Leaf Spy and Leaf Stat read the data from the Leaf.
You stated that Leaf Spy can pick up the low pressure on the rear wheels and flags a problem which to me means Leaf Spy is displaying each wheel's PSI value. Then you state that Leaf Stat also displays each wheel's PSI value. From this you then draw the conclusion that iPad can receive wheel transmissions and android devices can not. That does not make any sense. You just said that both Leaf Spy and Leaf Stat displayed PSI values so they both are capable of displaying data from the wheels. What am I miss here?
OK, I misunderstood what Leaf Spy was doing.
You're saying it's only reporting what the Leaf tells it, not collecting any data itself.
My Leaf dashboard has a graphic which can show which wheel has an inflation pressure problem. This is what I see when I drop the pressures to set up Leaf Spy - the Leaf's own display is showing the two rear tyres as under-inflated, which they are. Leaf Spy itself never reports anything - the display is fixed on zeroes for every wheel, however far I drive. Having started the Tire Reg process, nothing changes at all on the screen, and the process never finishes, however far I drive. However Leaf Stat on the iPad does display plausible tyre pressures. Going through the TPMS Reset routine on the Leaf doesn't improve things. Using a WiFi rather than a Bluetooth dongle doesn't improve things.
I am using a good quality handheld pressure gauge to set up the tyres for the tyre registration procedure. How close to 35/32/29/26 psi do I have to get? I'd have thought the spacing was more important than the actual value.
First, I have never heard of a Nissan Leaf dash having a separate warning indicator for each of the four tires. That means you have four tire warning lights instead of just one. For this to work the TPMS system would need a way to automatically detect the correct location of each tire after they have been rotated or the indication would be invalid the first time someone rotated their own tires. Up to this point the Leaf's dash has had only a single warning light.
If your Leaf does have an "Auto Registration" feature it would make sense that Nissan would drop the manual one that Leaf Spy Pro is trying to use. If this is true it is possible that the Leaf is now ignoring the command Leaf Spy Pro is sending to initiate a manual tire registration as well as never setting the status bit that indicates the registration has completed. This would explain why after you start the registration it never completes.
Garsh has the right idea. We first need to know if Leaf Spy is displaying the four tire pressures on screen four.
It would also help me understand what is going on if you could take an ELM trace and send it to me at the email address listed on the About screen.
Go to the bottom of the Leaf Spy settings menu and check the "Trace ELM (on restart)" check box. Then exit and restart the app and take a short drive (5 minutes will do). Then send me the TRC_xxxxx.txt file you find on the SD card in folder LEAF_BT_CAN/DEBUG_FILES.
A trace of you actually trying the tire registration would also help but that is more work (setting up the different pressures).
With the Leaf moving, when you go to the tire registration screen it should show you the six digit hexadecimal registration number for each of the four tires. A value of all zeros for each would indicate the tires are not register or the Leaf does not support manually registering the tires.