This is a simple Alfred workflow to to change resolutions on your Mac. It invokes the command-line utility bundled within avibrazil's RDM app.

The workflow was taken directly from Dan Schlosser's website, which has some other nifty workflows. I made/uploaded this version because Dan's workflow didn't behave as expected for some resolutions on my monitor--the output from the CLI tool indicated that the scale option ("-s") was causing problems. This workflow differs from Dan's in that it leaves out the scale option and assumes Retina/HDPI.

Type "res" into Alfred to start the workflow. The listed resolutions can be found in the resolutions.txt file within the workflow directory. You can get to it by right-clicking the workflow on Alfred's "Workflows" tab and selecting "Show in Finder". I'm currently using this on my LG Ultrafine 27" so if you have that (or a 27" iMac) you should be okay without editing the file.