If you notice that your camera's shot is moving on its own, it's likely that Auto-Pilot has been turned on.
To turn off Auto-Pilot, tap the More Options icon in the lower right corner.

Tap the Camera Assistant icon.

Tap Auto-Pilot. You should notice the white box that surrounds it go dark. This turns auto-pilot off.

Now edits will only occur when you tap, pinch, or drag your fingers on the app.