My Blog is about Technology.
I also am an Android app developer.And a Software engineering student so i know how to present an app.
My blog has 3000 to 5000 unique users/month.
I will show a banner of your app in the sidebar of the blog for 1 week.
Just a link to your app in the sidebar.
Check out the gig-extras to pick the promotion option of your choice.
I wish you great success with your app! :D