This app was mentioned in 4 comments, with an average of 1.25 upvotes
May sound silly, but assuming you have an Android phone, I'm happy I can customize my ringtone. My Apple Watch can't even do that yet four generations in.
https://play.google.com/store/apps/details?id=com.lehoang.customringtone&hl=en
Found a solution to this,
https://play.google.com/store/apps/details?id=com.lehoang.customringtone&hl=en
Its 99 cents and only works for S2 3g model and cannot update notification sound settings due to it being locked down by the carrier. Works great though.
https://play.google.com/store/apps/details?id=com.lehoang.customringtone
This is the one i use. It works fine. And you can send any size file to watch
https://play.google.com/store/apps/details?id=com.lehoang.customringtone
Indeed it does. And it's really easy.