How to disable Gatekeeper alerts on opening text files synced with Dropbox?
man spctl

That is good to know, although you can just do:

xattr -d YourFile.txt

This removes the quarantine attribute on files.

With spctl you can add WriteRoom to list of apps that can run. From

man spctl

EXAMPLES
 To check whether Mail.app is allowed to run on the local system:
       spctl -a /Applications/Mail.app

 To allow Frobozz.app to run on the local system:
       spctl --add --label "My Stuff" /Applications/Mail.app

 To forbid all code obtained from the Mac App Store from running:
       spctl --disable --label "Mac App Store"