Everyone's been asking about it. Everyone wants it. Here it is, the wifi calling app from the G2! I've installed and runs perfectly fine on my vibrant running JP3 froyo 2.2. My home network is weak so i can't really test yet. Kudos to @Official_Drizzy for the .apk
Install with your preferred method of install, I used astro just fine, or push it to /system/app via adb. Whatever floats your boat.