There are so many scan tool variants out there, hard wired, blue tooth, and wifi. I wanted something cheap with a wifi interface, since I don't plan on using it frequently. All my vehicles (Toyota, GM, Honda) are ODBII and this combo has worked well for my needs. I purchased the adapter on Amazon for $20. I opted for the the pro version of the app for ios @ $4.00, which unlocks more features. They have a free version for android and a pro version, as well.
1. Foseal car wifi OBD2 scanner (improved version)
2. InCarDoc app (Pro version)