The University of East Anglia have a live blog as well that updates their predictions based on statistical model [0] by Dr Chris Hanretty. Predictions are based on how results differ from the prior model. The model is explained in more detail here [1].
[0] http://www.ueapolitics.org/2016/06/23/eu-referendum-allnight...
[1] http://www.ueapolitics.org/2016/06/09/the-eu-referendum-what...
Edit: They moved their blog to Medium because of the demand: https://medium.com/@chrishanretty/eu-referendum-rolling-fore...