Hey, I have used the SEO Tools Centre but it doesn't worth the efforts. It is a basic tool which change the original concept of the writing. For example, in able to change the words by the synonyms, it wouldn't focus on maintaining the meaning of the context.
However, there are several other tools which words for free but gives an amazing piece of paraphrased content. You can opt to Paraphraser.io as it works on the basics of artificial intelligence and Natural language processing to make your content in the best form.
