Getting Amazon Appstore to Work.
Once you have installed Amazon appstore & got it to work the 1st time, the next time you try to return you will get the useless search appstore & black screen.
When this happens, use the back button to exit appstore, go to settings/apps/appstore/clear data. Back out of settings & press Amazon appstore again.
This time you will get the white and amber Amazon appstore smile in the upper left corner and either a black screen or a black screen with a create account button in the lower right. Use the back button to exit appstore again.
Press the appstore button again & this time you will get the welcome screen where you can log on & get what you want. (3's a charm?)
Thanks to Mav & all you others for all the help.