Renamed to Whistle, with a new icon.
Ring your watch from your phone: the settings page is now one big button, which buzzes the watch and lights its screen even when Cairn isn't open on it. No setup needed. Everything else moved under Advanced.
First release. Siren with escalating volume, vibration, screen strobe, double-tap to stop, find-it timer, and a journal of Bluetooth connection events. Experimental Bluetooth knock and leash, both off by default.