Google play store? What the heck is that? Just go to "App Store" on your IPhone. Search for "Sleep Cycle" - it'll probably be the first app you see. It's the one depicted above with the burnt-orange clock face logo. Hit "download" and you're done. Done this way it's free! I've NEVER seen any version in which Sleep Cycle costs even $0.99 - but even if it did cost a lousy buck, it is worth it. I just checked last night and done as I describe it is FREE.