With the recent advances in Machine Learning, strategies based on data could be used to augment wall modeling in Large Eddy Simulation(LES). In this work, a wall model based on gradient boosted decision trees is presented. The model is trained to learn the boundary layer of a turbulent channel flow so that it can be used to make predictions for significantly different flows where the equilibrium assumptions are valid.The methodology of building the model is presented in detail. The experiments conducted to choose the data for training the model, as well as to choose the model input features are described. The trained model is tested a posteriori on a Turbulent channel flow and the flow over a wall mounted hump. The results from the tests are compared with that of an algebraic equilibrium wall model and the performance is evaluated. The results show that the model has succeeded in learning the boundary layer and performs as good as an algebraic wall stress model.