Meaning of triangle with eye in "Life Is Strange"

I am just after the first episode of Life is Strange. Few times I noticed a triangle with an eye. For example: in school bathroom, on wall near school, in Chloe car and Chloe room. What does this symbol mean in this game and why is it in it?

The symbol is the eye of providence.

The symbol is not unique to Life is Strange. It exists in the real world, originally as a Christian symbol. In modern times it is often linked with conspracies and secret societies, largely because of its appearance in US government symbols (most notably on the $1 bill).

Whether it represents divine guidance, conspiracies, or if it's just Bill Cipher is something only the devs know and is unfortunately off-topic here.