apps4primaryschools.co.uk is a great place to start. The site allows you to filter by platform (Android or iPad), by age and or by subject. It provides an image of the app, pricing and a brief description. However, the links are not to the Australian app store. For Australian iPad teachers, when you find an app which you like, open a new browser, search the name of the app + iPad + Australian. This will give you a link to the Australian app store.  I am not aware if Android users need to do this for Google Play (guessing not?).