Automatic notification of real estate for sale is provided to a prospective buyer running a real estate app on a mobile device. A chirp beacon that is a Bluetooth Low-Energy (BLE) tag or iBeacon is attached to a real estate sign. The chirp beacon periodically broadcasts its identifier that is received by mobile devices within a range of 10-100 meters. The real estate app sends the identifier to a remote database to find a property IDs. The property ID is looked up in a merged database to obtain property information and directions that are displayed on the mobile device. Additional signs such as at busy intersections or inside the property may also have chirp beacons that cause the real estate app to fetch more information. When real estate app detects a nearby chirp beacon, an audible chirp sound is generated by mobile device. Selling agents receive valuable usage statistics.