Poritz, J.A. & Rees, J. (2017). Education is Not an App: The Future of University Teaching in the Internet Age. London: Routledge.
This is less of a "how to" book and more of a "why" book. It helps instructional designers get back to a key question: what is the learning we are designing intended to do? It is a critical assessment of the current preoccupations of many engaged in online and distance education. It's not long (134 pages), but makes you think long and hard about what the work of instructional design really is all about.