IntelliJ is an integrated development environment (IDE) for Scala and other programming languages. It integrates an number of programming tools into one application. We do not recommend using IntelliJ, but some people are used to using it or other IDEs such as Visual Studio or Eclipse and so we have instructions here.
Start by downloading and installing IntelliJ. You can use the free community edition for Creative Scala. When installing IntelliJ you will be asked a lot of questions. You can accept the defaults for the most part. When you are asked about "featured plugins", make sure you install the Scala plug-in.
Once you have completed the configuration you will be presented with a dialog asking if you want to create a new project, import a project, open a file, or check out from version control. Choose "checkout from version control", and select GitHub.
In the dialog box that opens change "Auth type" to Token. Now visit GitHub in a web browser. Select your account (top right hand of the page). Choose "Settings" and then choose "Personal access tokens". Generate a token. Call it "intellij" and select the "repo" check box. Copy the long string of numbers and text and paste it into the "Token" box. Now login to GitHub.
Install the SBT console add-on.