Synopsis:     This week Mark and Shawn wrap up their four-part series on Google Apps with a look at the Google Apps Marketplace and some of their favorite addons. Links: Aviary.com SlideRocket.com SherpaTools.com Pixetell.com TIPS:   Tech Tip of the Week: Display Changer -  changes the display resolution, runs a program, then restores the original settings.   Teacher Tip of the Week: GraphCalc – The Ultimate Windows Graphing Calculator