Why isn't there a Grndr app for straight people?

To be honest I am pretty jelly of the gays and their sexual openness.

I would think a match.com/grindr app would be huge. Something that would save me from wearing a sign that says single and open to anything. Instead I spend 20 minutes talking to a girl and ten bucks on a drink just to find out she has a boyfriend. Which is the ultimate douche move girls pull btw