I just bough Withings WifI scales and ran into a problem which I was able to fix, but I thought it worth posting in case others get it.
You need to run an application which you download from the Withings site in order to set the scales up with your WiFi system.
The app would not run because it was not from an apple cerfified developer!
I had had this issue before and knew I had to control click to open it and then all worked fine.
More about what to do here.
Hope this is useful
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