Go to the Visible Body website: https://www1.visiblebody.com/mobile_orgs/#en
Follow the instructions to download the app. You can activate the app either on or off-campus. Note: You MUST follow these instructions and click the link on the website to go to either the Apple App Store or the Google Play Store. Searching for the app directly will pull up a different version that costs $24.99. The links on the website take you to the app used by schools who already have a subscription.
Here is a screenshot of the wrong version. Note the title and the cost.
Here is a screenshot of the right version. Note that it's free and says "for organizations only."