My guidelines for choosing apps –

1. Exports to the camera roll
2. Imports from the camera roll
3. Saves to Drop Box, Google Drive, One Drive, Canvas, Edmodo or the web.

Apps–
All are free, unless otherwise noted.

iMovie – The best tool for editing from multiple sources and publishing to a usable video.

Skitch – Great tool for annotating pictures and Screen shots.

Tellagami/Tellagami EDU ($4.99 No VPP) – Narrate with and engaging avatar.

Sock Puppets Complete ($3.99) – Narrate with a sock puppet

Adobe Voice – Create and Narrate Slideshows

Doceri – Animate and Narrate demonstrations

ThingLink – Create a webpage with graphical links.

Pic Collage – A great App for creating graphics to use with ThingLink.