Google Now is an app for mobile devices that acts like a personal assistant, looking at things like your location, calendar and email to remind you that you have a lunch date, for instance—and what time you should leave to get there.

The search giant is dipping its hands deeper into its trove of user data, trying to make Google Now more useful with a few new features.

An update Monday will tell you when products you were shopping for online are available nearby in the real world. Search for a particular blender, for instance, and Google Now will notify you when you walk past a Williams-Sonoma store that carries it.