Use your favorite PBS characters to make your own stories with Scratch Jr.
Apps for content creation on a tablets are rare which is one of the reasons I love Scratch Jr.
I've mentioned it before it's so easy even your 4 year old can have fun, and with very little parent help because it's fully icon based for use by pre-readers. This new release with PBS characters could be a good way to get their interest started. Scratch Jr teaches sequencing and interaction events but everything is very immediately connected which keeps need for abstract thinking to a minimum, and no math needed. If your looking for a super easy square one place to begin this is it.