This add-on functions like a mail merge, but with a few more features. You can install it on any Google sheet, including a form response sheet. This allows you to create either a Google document or PDF from the form submissions. The add-on requires that you create a template document with embedded merge tags. These are easily created by closing text between double chevrons, like so, "<<your_tag>>" The template and merge tags may be formatted however you like.
Autocrat allows you to set up conditional merging, meaning you can create two (or possibly more) different templates and Autocrat will use the conditions you set up to choose which template is used to create the merged document.
I can see many applications for this add-on. Aside from those suggested in the video demonstration, I could see this being used for an automated note collector. You could create a form to collect information about meeting details with a field for longform notes. Once the doc is created you could then email it to any locations or services (IFTTT, Evernote). You would then have a copy of the document in both/all locations. This could also be used to create application forms. The patron would fill out a form and then Autocrat could automatically generate the application, plugging in the patron's submissions.