5) Loud Alarm Clock

Loud Alarm Clock has a few tricks up its sleeve for helping you beat the snooze button: It promises that it’s the loudest alarm clock out there, for example, and it also randomizes the alarm sounds that it makes use of so that you don’t get too familiar with any of them.
It has some quite nasty audio clips in its collection as well, from nails scraping down a chalkboard to a police siren (you can also use your own music, too)—however you will have to pay the in-app purchase before you get access to these grating sound options.