PSR-FIG Compatible Withings Body metrics Services API written in PHP.
I could not find a good API for Withings written in PHP that's up to par with their recent changes.
This one should fill all your needs.
Complete with oAuth1 integration. Also integrates nicely into Laravel's Socialite.
Input parameters can be found here: http://www.withings.com/api (and very often phpdoc'ed)
I only own the Withings Body Scale, so I can't input any data for their other products. If you do, and would like to extend this library, please send a PR with a fix