I just came across this wonderful graphic designed by @iPadWells and shared on iPad4schools.org. The graphic features some of the pretty basic tasks students can perform using their iPads. It also provides apps that go along with each task. However the apps mentioned in this document are just suggestions and you can use other kinds of apps to do the same task if you or your students are not familiar with the ones featured here. Check out this list of apps for more suggestions.
I invite you to have a look at this graphic and share with your students as well. Enjoy