To use the dashboard, make sure you've selected the "Dashboard" tab. 

As a user, you'll be able to see all the applications that you have been assigned. If it's the first time clicking on an application, and credentials haven't been set up for you, then you'll be prompted to enter your user credentials for the specific application. Once your user credentials have been set up, you'll just need to click on the application tile to be re-directed to the application of your choice and be automatically logged in. You are also able to check your credentials for any application in Teamstack, by pressing the 3 vertical dots in the bottom right corner of the tile, and then "Show Credentials". 

As a manager or admin, you are also able to access "Application Settings" from the dashboard. This can be accessed by pressing the 3 vertical dots in the bottom right corner of the tile, and then "Application Settings". From there, you're able to manage the application overview, and assign users & groups to the application .