If you've made a New Year Resolution to become healthier in 2014, you really should use Lifesum (formerly ShapeUp Club). Available on the App Store for iPhone, in Google Play for Android and on the web. Active members lose, on average, 6 kgs in 3 months and this year I personally intend to be one of them.
We made lots of improvements to Lifesum in 2013 and James Pember of Swedish Startup Space summarized them very well in a tweet: "Holy shit. The new @Lifesum app is beautiful. Masssssiiiive improvement!"