Unlike other applications that emits high frequencies sounds that does not work at all, this app goes straight to the point that you already know how it works.
Basically with this app you have the ability to use Strobe Flash from your device to confuse the agressive dog. Keep distance and point your phone to his face so they can not spot you. They will be confused for a while. It is very effective at night.
The other option is related to sound defense features.
Dogs hates the following sounds:
1 - High-pitch Frequency Tones
2 - Thunder - Dogs are commonly freaked out by rumbling thunder and thunder claps. Crank up the volume and scare the heck out of an unsuspecting slobber-bag!
3 - Wolves - Wolf howls and growls, even Werewolf attack noises will provoke fear on them. King of the jungle Fido is not.Use to startle dogs (as well as their bossy owners).
4 - Other Dogs Barking & Snarling - Vicious guard dog barks and throaty growls ought to alarm coddled frou frou dogs.
5 - Police Siren: Police, Ambulance and Fire Engine sirens. Stimulus overload. Make fools out of stimulus response-addicted neurotic mutts! Contrary to popular belief, vehicle sirens don’t hurt dog’s ears, but rather tricks dogs into joining in on a howling jag. Another “fool the dog” sound.
6 - Alert Sounds: Similar to Sirens.Overwhelm a yapping dog with a noise that is louder than its bark! Put the volume to the max.
The goal of this app is to protect you and your family from agressive dogs and bossy owners that threats you because of his dog.
Have this app in your pocket for any emergency.
Disclaimer: Continued use of the flash may dramatically decrease battery so use it wisely.
PS: Use a portable speaker to amplify the sounds. Bluetooth ones are more expensive but they also allow you to hide the speaker away from yourself, protecting even more your house against any attackers!