HeyMelody app early access version has been published by OnePlus on Google Play. The app provides OTA update services for OnePlus Buds and OnePlus Buds Z, Oppo Enco W51 earbuds and Oppo Enco X earbuds. The app is compatible with non-OnePlus devices as well.

source https://gadgets.ndtv.com/apps/news/oneplus-heymelody-app-download-updates-oppo-earbuds-android-compatible-play-store-2317985#rss-gadgets-all