Though $4.99, this app allows you to annotate video. For PE teachers, coaches, music teachers, science teachers or anyone else looking to make notes on physical actions
Designed for 1st-2nd grade students, Murky Reef combines reading and math skills in the context of exploring a coral reef. This is the free version, though there is a more robust version available for $3.99. Students can review numbers, sight words, and vocabulary. There is some reporting built in.