You can contact them, talk about what you're doing, and see if there's a possibility of partnership. If you're both startups in a true sense of the word, you might benefit more from such collaboration rather than competition.
Don't waste time on partnerships with potential competitors unless you just want to get hired by them. At best you're giving them a roadmap to make you irrelevant. Until you have users/revenue you really have nothing to offer but ideas to steal.