A friend who works for the Geek Squad at Best Buy told me that I should regularly check my liquid damage indicators as in is very important to know as early as possible if moisture has affected my phone.
The liquid indicator on the S6 is actually located on the SIM tray. On the left corner of the frame.
For future reference though, this is an Apple forum. For Android related questions you'll want to visit Android Forums at AndroidCentral.com
That's probably where you'll find the most helpful information for your device. If you ever decide to get an iPhone though, we'd be happy to help!!