This Morning item on mossies.

[Skiddy]

  sorry to burst the bubble on acoustic deterrents but

(1) you can get any tone generator app on the store for free, and 

(2)  http://www.which.co.uk/news/2007/04/sonic-mosquito-repellents-dont-work-112935/

I've tried them.

[Chris_S]

K4E, as I said I'm a cynic!

Just because you can hear it making noises in the audible range doesn't mean it's making noise in the inaudible range.

Phone speakers are optimized for speech which is quite low (300Hz-3400Hz), music is 20Hz-20 000Hz, but that's for your HiFi with big and clever speakers.  The small speaker in the phone won't do that without perceptive adaption.

The phone speaker isn't designed for sound outside the audible range (about what Hi-Fi range is), but the upper figure decreases as you get older), and in all probability, would have such a low power output at these inaudible frequencies, would probably be ineffective unless the mossie sat on it, since high frequency sound doesn't travel far (think hearing the bass of a party several doors along, but you can't hear the treble much), you'd need a lot of power to be able to fill a room.

In short, it's probably going to be just another smartphone app scam(?).

[kalkan4eva]

you lost me at "optimized" Chris_S
Skiddy, the free apps had poor reviews, the 69p one had good reviews. I've hardly busted the bank, although I have over the years on all manner of repellents. Seems to be thwarting the Welsh mosquitos at the moment...? Its hope over scepticism for me....just sayin.