A free program for Android, by Apps by evillf.

The eShop Collection: Game prices is a free and easy-to-use application that contains a list of all eShop collections, with more than 40 countries to browse. You can browse all of them at any time, regardless of whether you have the app installed or not, or whether you have it installed on your mobile device or tablet.

The app also has the option to get notifications about the availability of a particular item in a specific country, as well as the option to get notifications about the availability of a particular item in all countries.

The eShop Collection: Game prices also has the option to add items that you want to buy to your wishlist.