We recommend that you use the SumoMe list builder. It's fantastic and best of all it's free. You can read more about SumoMe at: http://www.sumome.com
First you'll want to install the Free SumoMe app:
The app will automatically add the appropriate SumoMe code to your storefront.
Now you need to configure the SumoMe app by visiting your store front
On your store front if you type in "sumo" and then press the up arrow, a dialog should pop up. (Note: ad blockers may prevent the dialog from appearing.)
Next you'll need to log in or create a SumoMe account
Next you can launch the Sumo store and install your apps:
Then install the list builder:
Don't forget to customize the design to match your store front!