Getty images; Tyler Le/BILike a lot of guys of the era, Eli Cohen had a great idea for an app back in 2010. But unlike many of his peers, whose musings were confined to bar hangouts and bad dates, he actually invested about $20,000 of his own money to try to bring the project to life. Unfortunately, his gumption only got him so far. Back then, "building software was painfully hard," he says. He burned through his budget well before it got off th…