Gunshot detectors and anti-drone defense topped our list of favorites from the 48 startups that presented at Y Combinator Summer 2016 Demo Day 2. We asked investors what wowed them and huddled with the TechCrunch team to come up with our pick of the 8 most promising companies. Check them out here, as well as our top 7 startups from the 44 that presented on Demo Day 1. Additional reporting by John Mannes and Matthew Lynley.