The Admin menu connects you to the most important administrative functions of a Study, including:
You will also see a count of participants in the header of the page as shown below:
Selecting this count provides access to various important shortcuts that will help you manage the participants of your Study:
The page header also includes an inbox icon that connects you to Messages - these are the private messages sent to and from participants. The menu also includes a green Compose button for sending / scheduling Email Broadcasts to all or a subset of the Study participants.