On Tuesday, OfferedApp plans to start letting anyone download a free app each day. It will offer an app that normally costs from US$1 to $10 to iPhone, Android and BlackBerry users each day.

Like with most things that are free, however, there's a catch. To download the applications, users will be asked to do something for an advertiser, such as respond to a survey, sign up to play a free game online or download a toolbar.

Once the user completes the action, the app will be sent to the user's e-mail address or mobile phone.

OfferedApp picks the daily app from any of those in the iTunes store, said Greg Schwartz, co-founder of OfferedApp. For Android and BlackBerry, it can pick any app from MobiHand, a mobile software distributor that offers tens of thousands of apps for each of the platforms.

On the back end, OfferedApp earns revenue from advertisers each time someone completes the offer. OfferedApp pays the developer for each app download, with the developers receiving their standard revenue share.