Angular deployment to Heroku - how to specify app

Question

I have written a small application in AngularJS, which works fine on my local environment, now I'm deploying to Heroku. But Heroku can't find my app. I must be missing a vital part needed to specify the build and deployment details. So what is needed to run an angular app on Heroku?

Here's what i've done so far:

• Used NPM to create a package.json file in the root of my project

• created a Procfile in the root of my package, specifying my app :

  web node app.js 
  

• added an angular buildpack to Heroku (https://github.com/nknj/heroku-buildpack-yo-angular.git works great)

when I use the Heroku CLI, for example heroku restart to refresh my dyno (and bear in mind i am running this from WITHIN the project root folder, so I shouldn't have to specify app name) I get the following error:

 ▸    Error: No app specified
 ▸    Usage: heroku restart [DYNO] --app APP
 ▸    We don't know which app to run this on.
 ▸    Run this command from inside an app folder or specify which app to use with --app APP
 ▸    
 ▸    https://devcenter.heroku.com/articles/using-the-cli#app-commands

Heroku can't find my app. Why? How does one tell Heroku how to bootstrap the app? Thanks.