Using TensorFlow on Android -- step by step code explanation

Nowadays almost everyone heard about machine learning or deep learning. But do we know what it is exactly and how to use it? In the matter of fact, I started to be more interested in this topic just couple months ago and it turned out to be indeed very interesting. I wanted to create an app which uses something learned by machine learning. I found TensorFlow, Google's open source library which was created for this purpose.