For many tech entrepreneurs, a first venture starts with an angel investor and a promising idea. For Neal Harmon, it all began with a cow. “I saved up money when I was 11 and bought my first cow,” he said. His brother Jeffrey had some color to add to the story. “And then he had a plan to make a million dollars—like if every cow had twins, by the time he was 18, he’d be a millionaire. That’s where Neal started, and we kind of followed after that.” Today, Neal, 43, and his brothers have come a long way from selling cows. Neal is co-founder and CEO of VidAngel, a service that lets users set custom filters to block out explicit content in streamed video content. Jeffrey Harmon, 38, is co-founder and chief content officer at VidAngel, which also produces its own original shows including “The Chosen” and “Freelancers” through …