This app watches price change on google shopping and notify price drop. It doesn't have history of price, it's not the purpose.
It's useful for black friday and other promotions seasons.
The app will only considerer the selected stores when searching prices
Beware about too much good prices, could be a fake store. Google Shopping will list it anyway.
How does it works:
1) Navigate on Google Shopping embedded on app and find the product of your interest
2) Configure the price that you want to be notified, and the stores you trust (The app will only considerer the selected stores)
3) Save the product to your watch list
Tip 1: Configure the price search interval on settings.
Tip 2: Sometimes Google shopping "hides" the better price in a link "More Offers" of the same store. If you get a notification and don't see the price when you enter the price list, try to find "More Offers" of the store.