You have $200. How do you drive mobile app installs?
You have $200. You can spend it on whatever you want. How would you drive mobile app installs most effectively?
In general though, I have found that the best use of your time and money is making a good demonstration video on YouTube (which improves all of your future posts/messages you distribute anywhere), and a PRMac release ($20).
I'm not endorsing PRMac, but I have had great success with it, and in the long run it helps your search rankings.
You are probably better off exploring other online channels and driving them to your market page.