I had a kindle fire for a very short time and I found an app called Out of Milk. I could scan my groceries in and add a price. the next time I would need that item I could scan the bar code, the item came up along with the price.
Out of Milk would also keep a running list of the prices that I entered so I knew if I was getting a good or great deal or no deal at all.
this is free off of amazon.