Which Bluetooth OBD to pair with Dr. Prius App

I am looking to purchase a BT OBD so I can use it with the Dr. Prius App to test the hybrid battery condition. Since I am only using it for this particular purpose, I would like to spend the least to get my task done. My Prius has 220000km on it and there are some preventative maintenance and repairs to consider if I decided to keep it for another 10 years. Hybrid battery replacement is my major concern (I think it could be a $4000+ job in Toronto).
If you are using one under $40 that works with the Dr. Prius app, can you please let me know? Thanks.