Thanks for your feedback.
I'll take your advice and we'll explain it on the website soon.
Actually it's a recurrent neural network using LSTM to analyse tweets sentiment. We trained the model with 1 million classified tweets about everything. We plan to get or make a training set based only on trading, our model will be more accurate.
The datapoints represents the number of tweets we analysed, it's categorized by positive, neutral and negative and it's represented on the graph.
The try link just wait for a sentence and return the entity sentiment (if you select entity-based analysis) or the overall sentiment. It's not perfect and we are currently working on algorithm improvement, we expect some feedback in order to know if people would use that kind of information/service. One of our next goal is to cross technical and sentiment analysis in order to be even more accurate about the price prediction per coin.