I got 85 users on The Build Nation. for a social network the more number of users there are on the app the…

I got 85 users on The Build Nation. for a social network the more number of users there are on the app the better. How do I market a consumer app ?
I honestly don't know what to do but then I got an idea. I am printing a flag and then sticking it to my scooter so that everywhere I go in the university people could see it and try to use it. Stay tuned for the upgraded scooter