Whether it is finding ladies toilets on the London underground, identifying bird songs, forecasting snow conditions at ski resorts or just buying stuff online, somebody, somewhere has come up with a clever little computer programme that lets you do the task from your handset.
The industry has grown up around the iPhone. More than 140,000 different iPhone applications have appeared since Apple opened its Apps Store on iTunes to outside developers in July 2008.
Although it is the dominant player, there are many more to choose from including those from BlackBerry, Microsoft, Google, Nokia, and Samsung.
Applications rarely cost more than a few dollars or the equivalent in other currencies to download. Many are free.
But already the app market is worth nearly two and a half billion dollars a year, according to data from AdMob, an advertising company.
Other smart phone brands are striving to…