Would you like to have biochemical and cell-signaling pathways at your fingertips? iPathways provides an enormous collection of biological pathways in a convenient format. Users must register for a free account, and then they have access to all of the content. Pathways can be organized by title, date, or size, and users can browse them in the same manner that one sifts through hits from a search engine. One useful feature that is not included is an alphabet shortcut—so one cannot simply jump to the models that start with the letter “P”, for instance. There is, however, a search feature that allows one to easily find a particular pathway of interest. One of the most useful features of the app is actually rather buried in the “about” section under the subheading “tips.” This page is essentially a how-to for the app, and it provides a lot of helpful information.