When the T-Mobile G1 debuted in October 2008, there were a number of features and services that were missing from the Android experience. People wanted to sync with their Exchange server, so Touchdown managed to fill a gap. Others wanted to sync their to-do lists, so Astrid added sync support for Remember the Milk. In the absence of official support, talented developers emerged to meet consumer needs.However, many of the great apps that everyone loved have been challenged by official releases fr