And You? Have You Received The Letter?

According to this article (link), more and more APPs developers are now receiving letters for paying licensing fees for patents. In the specific case disclosed in this article, the company "sending the letter" is seeking 0.575% of US revenue until the expiration of the patent plus past usage which is quite a nice revenue considering the potential market of an APP. In any event, APPs developers should really be cautious with IP.