the withings scale in the apple store has wifi, You do need their app to set it up, but once that's done it updates to their servers via wifi, which will push updates to your phone.
I purchased their blood pressure cuff in the past couple weeks, it works pretty well, I did have to read the manual though, as it doesn't automatically push the reading, you have to select a user before it sends. It's easy to do, but not intuitive.
It is a little slow though, readings can take a few hours to show in the health app, I don't know why though as they'll appear in their app fairly quickly. I'll have readings appear in their app, but not show in the health app for a while. I'm still trying to figure out the timing.
The setup was a little kludgy, when signing up it made me enter a weight (which I approximated), then it asked to sync with HealthKit, it pushed that entered weight into health, I had to go into both apps and delete that one entry, and then the witihings app pulled the correct weight from health. If you're going to sync anyway, don't ask for a manual entry until after you've checked.
(my scale is a weightgurus, but it's bluetooth to the app, so you must have their app open to push readings, but they also instantly show up in health)