iPhone app helps you predict which seat will become vacant on the train

 A new iPhone app called Densha de Suwaru (sitting down on the train) by Velc helps you make a database of strangers you commute with regularly.  For every passenger you create a list of features, such as which stations they ride between, at what days and times and on which line, along with gender, age, and other identifying details.  The app allows you to make a cartoon-like image of each of your fellow passengers.

The more data you add, the better you will become at predicting which seated passenger will be the next to leave the train.

In Japan, particularly in Tokyo, where it is not uncommon for people to spend 2 hours or more commuting by train every day, finding a seat is an important concern.  In 2005, a book about how to find seats on packed trains became a best-seller book.

The app can be purchased at the iTunes store, but it is unclear whether it is available in languages other than Japanese.