OnePlus has released an early access version of the Hey Melody app. It can be used to update the firmware of some True Wireless headsets. The main difference between it and the OnePlus Buds app is broader support.
But not only does broader support mean more sprout support, but this app also works on more phones. The OnePlus Buds app can only be installed on corporate phones and only on newer models. You can’t use anything older than the OnePlus 6.
Note: if the Oneplus Buds Application is not compatible with your device you can use Hey Melody App
In contrast, HeyMelody works with other brands of phones, including older devices. I need Android 6.0 Marshmallow, which is now quite old.