The location control adds the ability to precisely track your position using GPS coordinates. This type of information is essential when working remotely or in new areas. They are best used as a small part of your normal documents as they have a more complimentary type of use.
To add controls to the app builder simply drag the control into the form builder plane where ever you choose to add it.
In the mobile app you can either input your values directly or have the mobile device add it in for you by pressing the 'Capture GPS' button next to each field.
In the web app you must manually input your coordinates in each field.
Each control has it's own settings which are fairly simple to use and configure.