the app is not actually installed.
I click on "add" button and on another "add" in the "add app dialog"
I get to the canvas with "newinstall" in the query string, but the app is not actually installed, when I go back to the about page I can add it again - I see once again the "add this app" button.
The bug is intermittent but happens too often ~30% of cases for me in Firefox.
Users also complain about this