A couple of decades ago it was common to see panniers like Axiom's Kingston Commuter Pannier, which were prevented from flapping up and down on the rack by a hook attached to an elastic strap. These days, that system has been superseded.
The attachment system is poor – one of the worst I've seen on any modern pannier.
Axiom's Corker has a couple of functions that other multitools miss, adding to the usual collection of Allen keys and screwdrivers a bottle opener and a corkscrew. Cheers!