Test Run: Addappt, a Connected Address Book for iPhones

You've probably heard this story before: A friend loses his cellphone, buys a new one and then invites hundreds of people on Facebook to join a group called “Lost my phone. Post your numbers please.”

As if that weren't annoying enough, he has bought a new phone and switched to another number, so you have to go into your address book and add his new digits. If you're anything like me, over a few years your address book has turned into a hopeless mess of duplicate entries, outdated numbers and out-of-date job titles. (And don't even get me started on what syncing up with Facebook did to my iPhone address book.)

That's why a new, free app called Addappt piqued my interest. It's basically a connected address book that stays up to date. If my friend using Addappt edits his contact information with a new phone number or e-mail address, for example, it shows up in my Addappt address book, too. If he adds his home address, I can even see what time it is where he lives so I can decide when it's best to call him.

The changes go both ways - any edits made inside Addappt merge with the built-in address book on the iPhone and iPad, so I don't have to worry about updating entries there, too.

But what about privacy? After logging in to Addappt for the first time, the first screen you see is a rather reassuring message: “We will never spam you or your contacts. We will never sell, rent, share your personal information to 3rd parties. Never, ever!” The company also makes this promise in its privacy policy on its Web site.

At this early stage, you have to enter your e-mail address into the app to request an invitation from the company. This serves two purposes: to ensure that Addappt can scale up properly and also to make sure the e-mail address you're using to identify yourself is actually you.

“ That way, one can't enter bill.gates@microsoft.com and we connect you with Gates's contacts,” said Mrinal Desai, a founder of Addappt. He says the company plans to make money eventually by offering paid features inside the app.

The app is available for only Apple's mobile devices, but Mr. Desai expects to release an Android version by the middle of next year.