Why do all that when you can whistle or clap and and let your phone tell you where it is!
Yoo-hoo! is a whistle and clap detection app. Yoo-hoo! will be listening for a whistle in the pitch range you're comfortable with and can also listen for a loud double clap if you can't whistle!
It'll play a song you've set and vibrate for the duration of your song when it hears you.
It also has a graph that updates every half second so you can see the waveforms from the sound around your phone.
Its capable of listening for frequencies in the range 500 to 1350 Hz and has a maximum listening range of about 9 meters.
Now you can rest easy knowing your phone is just a whistle away! (Or Clap!)