Launcher is a great little app that has one purpose: to enable you to launch an app or (even better) to do a specific action within an app all from the Today View of Notification Center. Launcher uses something called URL schemes to allow you to quickly launch and send an email or iMessage or create a shortcut to a website that you frequently visit. You can also launch many different apps on your device with one tap. Launcher also has a Special Launcher action that enables you to access device storage, memory available, create a countdown, check the battery, check the wifi are just of the few special actions available.
Perhaps the most powerful use of Launcher for me is the ability to launch a specific action within an app. I use this to launch specific Google Sheets and Docs from one button. Each Sheet or Doc gets its own Launcher button so that I can quickly access the information in those docs and spreadsheets very quickly, get the information I need, and then move on to my next task. My district uses Google Docs and sheets to hold and share much of the data and information we use as a district and these Launcher buttons allow me to get to that information so quickly that I almost seem like a wizard to my colleagues and our students. Launcher easily saves me 30 minutes to an hour each week.