Some examples of worksheets and activities:

Fan Favorite iPad/Kindle Apps

Khan Academy Kids is a free app available on iOS, Google Play, and Amazon Appstore. Khan Academy is not subscription-based and does not show ads. The app's curriculum is geared toward ages 2-8, so there are many options for individuals at various developmental levels. 

PBS offers several free "KIDS" apps, but we primarily use "PBS KIDS Video" which has shows like Arthur and Mr. Roger's Neighborhood, and "Play PBS KIDS Games" which has games based on these shows. Both apps are subscription-free and ad-free. These games and shows, along with some additional features like music and e-books are also available on the web at https://pbskids.org/.