I had doubts after reading some reviews as to whether the Polar Balance would fulfil my expectations but I need not have worried. The Polar Balance setup and sync works perfectly with the Polar Flow app and website. Setting a target is done on the Polar Flow site first, the app let's you know if you are on target.
I use a Polar M400 fitness watch and H7 heart rate monitor and adding the Polar Balance updates the settings on my watch to current weight.
The inclusion of a BMI chart is a little outdated though and can be off putting for those who follow an intensive training program. It doesn't allow for fat percentage to be added or measured but I use more than one app for fitness tracking so this isn't a major issue for me.
If you want quick, clear and consistent then the Polar Balance is a fantastic investment.