K9Alert is built for workers who approach unfamiliar properties on the job — delivery drivers, mail carriers, utility workers, couriers — not dog owners or neighbors. It uses crowdsourced, GPS-based reports to warn users in real time near locations where aggressive dogs were reported. Other users can mark reports as still active or resolved to keep them current. Alerts still work with limited connectivity via local caching. Free 30-day trial, then $12/year. Built by an independent developer.
