Like much of the Internet, many free iPhone apps have embedded advertising as their revenue model. The most popular tip calculator, and third-most-popular app in the finance category, CheckPlease, added advertising across the top of its calculator in its version 3.3 release (Nov. 12).

The current sponsor? Bank of America mobile banking, which has the second-most-popular finance app in the iPhone App Store. The advertising is handled by Mobclix, an advertising network focused on the iPhone and Android markets that debuted at TechCrunch50 in September. In a half-dozen visits, I've seen only the BofA ad. But the developer, Hardy Macia, says he's seen several movies advertised on the app. 

Clicking on the BofA ad (first screenshot) takes users to the BofA landing page (second screenshot on right) hosted within the App Store environment, i.e., the pages are not displayed within the normal Safari environment. The only navigation options are:

• Learn more (see 3rd screenshot)
• Download (see 4th screenshot)
• Visit bofa.mobi
• Close (the X in the lower-right) which takes you back to the CheckPlease app

CheckPlease is a product of Catamount Software which has developed mobile personal finance software since 1994, when it launched PocketMoney for the Apple Newton. PocketMoney is now available for the Palm and iPhone. The company just added an ad-free version of CheckPlease for $0.99.

The free CheckPlease iPhone app has been downloaded more than 200,000 times according to its developer and owner of Catamount Software, Hardy Macia.

      CheckPlease iPhone App                       BofA landing page

          Learn More page                                 Download page (note 1)

Note:
1. Surprisingly, the buttons on this page are not clickable. To download the BofA app, iPhone users must close this screen and open the App Store button on the home screen(s) of their iPhone.