If you have a bunch of little files and need to make a big one, this is your app.
Assembler is a godsend for screenwriters working in Fountain. Write your scenes separately, then combine them only when you need to.
If you have Highland installed, you can even open the new file directly in the app.
For writers working in plain text or Markdown, Assembler makes it simple to combine sections and chapters.
If you find yourself working with .csv files -- such as PayPal exports, or Kickstarter backer reports -- Assembler makes it quick and easy to merge them into a single file.