Here's our short video tutorial on using the location app to embed Google Maps in your tab. Check below the video for instructions on adding multiple locations...
Adding multiple locations
The best way to add multiple pins to your Google Map is to use use our Google maps html template (not the app, the template) and the Google Maps maker: https://mapsengine.google.com/map/
Build a map with the pins that you want there, then get the embed code for the map you've made. Next, you'll want to take the URL that is in the <iframe src="URL"> tag from that new embed code. Go to the template, and use that url for the src of the iframe that is in the template.