No, you do not need the CLIPR button to use the Sporfie app.
When you join an event and there are cameras filming, an orange icon will appear on the bottom right corner of the screen. When that button is tapped, the past :15 seconds of the game will be captured from all angles.
The Clipr button is an optional piece of hardware that allows you to save clips while your phone is in your pocket or while using other apps. It is especially useful for coaches who can’t have their phone out with the app open during the entire game.