Missedqueries pulls your google search console data, compares everything it ranks for with the content you wrote.
With the data, you can filter through queries you rank for, but never wrote about. You can use filters to find easy pickings, missed queries on page 2 or position 4-10.
Use the data to target missed queries, hence the name. Add one or two sentences about the query, and watch you rankings go up.
It's quite easy, which is the point.