Price Notification Apps/Websites? to Receive Alerts When Price Is Reduced

Is anyone aware of an app or website that has the ability to notify you when the price of something drops?

For context, there is a blower vac I would like to purchase from Bunnings, however as it's not urgent I can hold out until a better price pops up there (or elsewhere). Would like to save the hassle of checking the website periodically and would prefer to be alerted when it comes on special.