I built a fun thrower for small aerial targets like paintballs wiffle golf balls. It takes a lot of practice to start hitting the tiny targets but it's even harder to find a volunteer that will spend enough time throwing for you to help you get that good. Hopefully this will spark some ideas for your own build.
As I explain on my website, this project had three requirements: 1. be completed within a few hours, 2. cost $0, and 3. remotely launch small targets 8-12 feet in the air. So this is definitely version 1.0 and I already have several revisions in mind. I did achieve the three requirements and I was shooting that same afternoon. If you are interested in the build process, the details, and pictures of the build, check out
Tiny Target Aerial Archery Thrower Build