I just find this app to be handy. Thanks to the helpful little share extension and smart notifications, the app is there when I need it and out of the way when I don't.
The app is free, but to take advantage of all the features which includes the price monitoring, a modest subscription service is required. Be sure to check out Lookmark. It's a great took and a convenient way to save all the best new apps and other media content that you don't want to forget.