Fillable Document is a great add-on for Commercial, Educational as well as Non-Profit organizations for all your document automation needs. 

Quota is applied per month and per person to the following

• Document generation - how many documents (Google Doc, Slide, PDF, etc) can be generated in a month

• Bulk document generation - how many documents can be generated in bulk from Fillable Document for Sheets in a month
  
  For example, "2000 docs per month" or "2000 Bulk docs per month" means that the user can generate 2000 documents via Fillable Document in a month

• Responses - how many form responses can be saved in a month
  For example, "10000 responses per month" means that the end users can submit up to 10000 times to forms via Fillable Document in a month

Free vs Paid plans:

• The Basic plan for "Fillable Document" is free with a limited quota to help users familiarize themselves before buying.

• The quota resets at the start of every calendar month (1st of every month).

• For professional features and additional quota, you can take a paid plan.

Note: A Single license works for the Fillable Document add-on across Google Docs, Google Slides, Google Sheets, and Google Forms.