Co-Star is an astrology app that uses NASA data and real human astrologers to provide personalized daily horoscopes and birth charts. The app allows users to add friends to compare natal charts and see compatibility, and receive daily push notifications based on their horoscope. Co-Star also offers premium features such as a complete personalized report on how you love and why, and a feature for couples called Eros, which provides insight on how to navigate everyday relationship situations based on zodiac compatibility.

The app has been featured in publications such as the New York Times, Vogue, and Vanity Fair, and has received praise from celebrities such as Dua Lipa and Conor Oberst. Co-Star aims to use astrology as a framework for understanding ourselves and our relationships, providing a shortcut to real talk in a sea of small talk.

Co-Star can be followed on Instagram, Tiktok, and Twitter, and users can contact the app's support team at horoscopes@costarastrology.com. The app also assures users that they do not engage in creepy data practices and provides a privacy policy and terms of use on their website.

Overall, Co-Star is an astrology app that offers personalized horoscopes and birth charts, as well as features for comparing compatibility and navigating relationships based on zodiac signs.