This is the ultimate natural safe-driving whistle — it works just as well as the app you tried. Click on the e-shop.

to avoid accidents with a dog without a radio, only with open windows in the vehicle and the smartphone volume at maximum (scares seven out of ten dogs)

The neighbor's dog barks at night and disturbs you. You don't sleep well. Dogs can hear it up to 50 meters away from your bedroom, if you have a smartphone with loud speakers.THE MAXIMUM is 50 METERS where DOGS CAN HEAR it. ONLY with the SMARTPHONE SPEAKERS,