According to a forecast, the worldwide smartphone sales surpassed the world PC sales at the end of 2011. Smartphones are a kind of mobile handheld devices with phone capability or mobile phones with advanced features. Typical smartphone features include microbrowsers, emails, short message services, mobile games, GPS, et cetera. The feature of high mobility and small size of smartphones has created many applications that are not possible or inconvenient for PCs and servers, even notebooks. Location-based services (LBS), one of mobile applications, have attracted great attention recently. This research proposes a location-based service, which uses location information to find travel route anomalies, a common problem of daily life. For example, an alert should be generated when a school bus misses part of a route or a pupil does not arrive at school on time. Different kinds of route anomalies are discussed, and various methods for detecting the anomalies are proposed in this chapter. The major methods use a technique of incremental location search, which finds matched routes as the search route is entered location by location. An alert is generated when no matched routes exist. Preliminary experiment results show the proposed methods are effective and easy-to-use.