This app defines 471 key terms for instructional designers and hyperlinks to related terms. It's great for new designers, helping them reach competence of knowledge, but it's also a valuable conglomeration and performance support for experienced designers.
When you tap on a term, the definition displays. Terms have hyperlinks to related terms. Tap on the hyperlink to get its definition. A light bulb icon in a definition indicates a practical tip. Having trouble reading it on a phone? Just pinch and zoom to enlarge the text size.
The app also contains alphabetical, categorical, and search functionality, in addition to standard scrolling and the aforementioned hyperlinking.
The app is currently only available on Google Play and costs $2.99—but programmers don't come cheap, so consider the tradeoff.