I've used the
PLX KIWI 2 wifi
for years with Apple / iOS 5-8
On REV / OBDScanner / CommandDASH app / Harry's Lap Timer
The obd is not compact - cost is 70$
Does have password setup/ once done and linked ur set.
Picking up the IKKEDOL VGate w auto sleep 30$
I like to try a compact version - the PLX can get cumbersome.
Here are few pics from REV and COmmandDASH