To release a new app version, first navigate to the App Versions page shown below, located at Settings->App Versions.
Then select the platform you would like to release by clicking on the appropriate "Edit" hyperlink.
After clicking on the "Edit" hyperlink to the left of the current Platform app you will be redirected to that platforms' App Versions Edit page. To release a new version to users, click on the "Release" button to the left of the desired version under "Available Apps."
App Versions Edit
After Clicking on the "Release" button to the left of the desired version under "Available Apps," a Confirm Release Prompt will be populated above "Current App." Once you click on "Confirm Release" in the Confirm Release Prompt, the selected version will be made available to users.
Confirm Release Prompt