SacLib This is a Sacramento Public Library app that allows you to search for books, place holds, get reading lists, and follow the library on FB and Twitter. It's a bit slow sometimes, but good stuff.
Sacramento Transit: AnyStop This free app has all the transit schedules in Sacramento. GPS enabled - good for finding stops near you. Needs a trip planner.
Sacramento Real Estate This app is a good way to search houses for sale in the Sacramento area that are listed by Robert Locke. There is a call agent button and a sophisticated search function - but it's just one realtor.
Sacramento News An aggregator for an impressive selection of local Sacramento news sources. Keep in touch with what's going on locally on your phone. Great app, works well, easy interface, flexible search.