The app works fine so long as you uninstall it and reinstall it every time you want to use it!. Otherwise you get a wierd error message Saying the app does not work because it is not registered. No wonder its raring is only 2.6 out of 5 stars. I wrote this five months ago. Then a trouble free spell followed but today it's back to being useless. todays stupid message is " the scan can not commence because the app can't be registered" Such a well respected company should be ashamed of this app.