What smart scales link to health app?

Do you mean the Apple Health App or the App that come with it?

Are you sure. The data sheet calls the app Health Mate app and not Health which is the Apple one. I beleive the Fitbit has a link to Health as my wifes fitbit syncs to her health app. I dont use fitbit so Im looking for a direct link if pos

According to the spec sheets:

http://www.apple.com/shop/product/HB930ZM/B/withings-smart-body-analyzer

Withings seems to advertise they support the Health app directly, while others maybe not so much.

Fitbit, according to other reviews does not seem to do this, but instead integrates with their own fitbit app. Garmin is the same.

Essentially, what I am seeing is if the company makes an effort to integrate into Apple's Health app, they get put in the apple.com store inventory.

I have the Withings, it works seamlessly with the app.

Withings (now part of Nokia) does have their own app but they also can be integrated into the Apple Health app. I have the Withings scale and use the Apple Health app.

"...and use the Apple Health app."