Mostly from the papers:
Short for application software: Software designed to accomplish specific user tasks (in contrast to “system software”).
While e-books are single files that require specific software (e-reader software), apps (being software) run by themselves.
A digital story is defined as a ‘multimodal narrative’ text comprising pictures, music, speech, sound and script.
Whereas books are ‘adapted’ for screen, books are ‘remediated’ as apps.