UX/UI Designer for Fitness Start Up

The first version of our app is online and we are looking for a UI/UX designer to help us improve some elements of the design based on the user feedback we received from the first users. The person preferably has interests in the area sports/nutrition/health, because that is the area he/she will work in. The goal is to take the existing app and make some UI/UX changes within the framework to make the app better and easier to use.