With a Product Model open, the app drop-down is located at the top left of the page, clicking on the app icon, app name or the down arrow, expands the app menu.

Just below this, there are four headings, 'Business', 'Environment', 'Health', and 'Regulations'. Each heading has its own selection of specific apps related to that field of analysis.

Clicking on any of the app icons from the grid will open that particular app for the Product Group or Product that is currently active.

The active Product Group or Product is shown to the right of the app drop-down, in the screenshot below, the 'Ball Pen' Product Group is active.