I think I've encountered text analysers that only looked at single aspects of personality before (e.g. agreeableness and extroversion): this does all the big five traits and more. I don't think I've encountered anything in regards the eight Jungian functions though (I was looking on Google Scholar months ago)...I know @ClownsandEntropy has been looking into doing something along those lines in regards forum posts, which would be a very good project to attempt.Gain insight into how and why people think, act, and feel the way they do. This service applies linguistic analytics and personality theory to infer attributes from a person's unstructured text.
You need text written by the person whose personality you're interested in. It should contain words about every day experiences, thoughts, and responses.
For statistically significant results, you need at least 3500 words and ideally 6000 You can still play with the demo if you have at least 100 words, but you should take those results with a grain of salt.