Itouch apps, is there...?

...an app to find your phone? Not an iPhone an lg octane. I really need it! I'm going traveling later today or tomorrow and need it! I have a feeling my sister stole my phone on thursday or Friday, bc she had to pay for my last phone that I had for 4 months and she feels cheated (she bought it bc she broke my first phone). I need to know if it's in my house or at her school or what so is there an app, or maybe a website to track my phone??