I have noticed some of the apps from Amazon Market that do download, do not always run. For some, I have found this workaround can help: 1. From Amazon market, download Z4ROOT and RootFile. 2. Run Z4ROOT and permanently root the device. 3. Run RootFile, navigate to /SDCARD/DOWNLOAD 4. Copy the app that was downloaded 5. Navigate to /SYSTEM/APPS and paste.