If you're trying to delete a Mac app but can't because it's still open, don't worry! There are a few ways to fix this issue.

If you receive File in Use. The action can't be completed because the file is open in another program even if file is closed in another program, see this.

Jugalkumar Kshirsagar asked how to delete a file that Windows insists is open. For reasons that should be obvious, Windows can’t delete a file—or move one—if it’s in use by a program.