I have followed the instructions several times but always end up on the "Thank you so much for your interest in Arduino Create Chrome App and for signing up. In the next few weeks you will receive an email from us about the private Betatesting." page. I have recieved that mail and still can't install. Also the chrome store link is 404.
Please email betatesting@arduino.cc with the Google ID you are logging in with on the Chromebook. Since the Chrome app is in beta, only a trusted set of users can install the app. If you are not logging in with the email you signed up from the waiting list it will not work.
I have mailed betatesting@arduino.cc concerning this issue and the last reply I got was
In general we would kindly ask you to report any other issue/question on the Forum at this page Chrome App - Arduino Forum, as other users may have encounter the same problem or had the same idea!
@Cerasus we need to test the standard flow we will use when the chrome app will be public, we cannot email every Create user the link to download the app