It's called something like game call app. There was a thread on here a week or so about it with the links to download it. I bought it and downloaded it. The sounds are not that great. Actually I doubt they would even call in a coyote here where I hunt. They are copied sounds that he has added to the application.
One thing though, once you unzip the file, if you go in and look at the file list you can see and play the mp3 files that are in the app. on your computer.
If you wanted to you could just delete those mp3's and replace them with your own.
Primos has an iPhone app. also. I think it has some deer and elk on it as well as predator sounds. From the reviews I read on it, it isn't that great either.
Search google for iPhone apps related to hunting and you will find them.