Caltroid is a Caltrain schedule application for Android devices.
The usage is pretty simple. Two buttons determine the day of the week and direction of travel. With spinners you can select departure and destination stations. The trains and their departure and arrival times are shown below.
Finally there is a button to locate the nearest Caltrain station using GPS.
The source is licensed under the Apache 2.0 license.
More information on Caltroid, including the source download information is available in the initial blog post announcement.