New apps take a long time to get created the first time. Not just minutes, but sometimes hours. Can you check again? The is a good chance that you can now run each of the apps that you created.
I experienced the same issues creating a new app as a sandbox application.
Not sure if this is realy the issue, but when i create a new app, make a lot of change, including security, the deployment seems to fail.
My steps right now to create a app: