A new app called OnePlus Health has reportedly appeared on the Google Play Store. It has ostensibly been developed to accompany the new fitness band and smartwatch coming soon from this brand. Tech bloggers claiming to have torn its APK down have posted faces and UI snippets for either device.
https://www.notebookcheck.net/OnePlus-Watch-a-new-leak-seems-to-confirm-a-round-face-while-the-Band-s-UI-is-exposed-in-detail.514072.0.html