I recently updated River Flows to support some of the Windows Phone 7.5 (Mango) featues like multiple live tiles and scheduled task agents. The new scheduled task agent updates the background images of the live tiles every 30 minutes (great post on how to generate live tile background images)
Everything was great until I went to submit my app to the marketplace. It turns out there is a list of unsupported background agent APIs that can’t be in any assembly references for a Scheduled Task Agent project. Initially I had my Windows Phone Application project structured with a class library that was referenced in both the Windows Phone project as well as Scheduled Task Agent project. I had to re-structure the solution to this:
Once I had restructured the class libraries so that my Scheduled Task Agent project didn’t reference any unsupported APIs and I was still able to have good code reuse, the marketplace submission worked.