I get a warning of another copy of the app

Look in your Dock and menu bar; does Time Out appear more than once?

If it's in the Dock more than once, you can long-click or right-click on the Dock icon to display the Dock menu for the app, then choose Options ▶ Show in Finder to reveal the app in the Finder. Do this for each to find the one that shouldn't be there — it could be in your Downloads folder, or in a subfolder of Applications if you installed both from the Dejal site and the Mac App Store.

Once you find the duplicate, quit that app (by double-clicking the app icon to bring it to the front, then press ⌘Q), then move it to the Trash and empty the trash.