This is a speed reading app, or tool, that allows you to paste in your text and that subsequently helps you reading it. It does so by flashing the words of the entered text in chunks. By default, the tool flashes one word per chunk, but you can change the chunk-size to a higher amount.
You can use this speed read tool to increase your average reading speed by practicing. Set the Words Per Minute rate (WPM) higher than your current reading rate. This will help you to read faster than you normally do. You're forced to read at the given rate, because it prevents you from regressing (as explained below). you're forced to read at the given rate. Slowly, but surely you will get used to that new rate. Even if you're not interested in increasing your reading rate, you can still use the tool to read your texts!
This tool prevents you from regressing (re-reading). When you read a text without a speed reading tool, you might re-read one or more sentences when you lose focus. The problem, however, is that you will lose focus when you regress. You should just continue reading, and when doing that, you will find yourself understanding and remembering more than initially thought. If you want to you can still re-read parts after finishing reading.
Another benefit is eliminating subvocalization. Subvocalization is the voice you hear in your head when you're reading a text. The downside of subvocalization is that the voice can only go as fast as your average speaking rate, which lies around 150 words per minute for most people. This then limits your reading speed. Since this tool can flash words at a faster rate than you normally read, it renders subvocalization impossible.
A few tips for reading texts faster (when not using this tool):