Mac: Switching apps on macOS with the Command+Tab shortcut is great as it is, but there aren't any built-in tools to customise how the app switcher works. Command-Tab Plus is an app switcher that adds just that.
First off, Command-Tab Plus adds a number shortcut, so you can easily switch to an app without tapping a bunch of keys. Beyond that, it can also isolate workspaces so apps in one space don't appear on another, and it can hide inactive apps entirely, which is handy if you have a lot of apps in the background that you don't need showing up in the switcher. You can also customise the appearance if you want, changing the border colour and background colour. Command-Tab Plus is a little pricey at $14.45, but there's a free trial if you want to give it a spin before committing.