Spin Rewriter 5.0 technology was a previous edition that allowed their clients to use the basic article rewriting system.  Their newer versions over the years have just kept getting better and better.   The new Spin Rewriter 9.0 technology gives you the option of assigning variables to your content.  Their software is dead easy to use.  In just three steps you can have up to 50 uniquely spun articles.
For this purpose, humans have created numerous rewriting tools to save time and use all words available in the English dictionary. Rewriting tools use millions of synonyms made available to them through artificial intelligence and instructions given by the human mind. If you hire the services of a content writer to rewrite/create content for you, they will charge you a lot. Big organizations can afford this but small startups and students can never afford the services of professional writers.    
Some of you may be wondering if we would class Spin Rewriter 9.0 as being a scam? Well, the simple answer to that is no, I wouldn’t say that this software is a scam at all. Yes, the software is quite expensive and the sales funnel is designed to make both creators and the affiliate marketers as much money as possible, but I wouldn’t say its a scam.
As we all know, Yahoo!Answers is the largest world’s question and answer community. You can attract targeted customers to your site and generate sales with AnswersChief. AnsweriChief can automatically handle all your Yahoo!Answers work.We have tested, AnswersChief fully,we know it can bring customers for you every day, and it can become a 24 -hour non-stopping money-making machine.
It is a widespread technique in SEO and SMM, involving the rewording and rephrasing of article. As a result, user will get a unique and original content based on the sample article. With the help of any paraphrasing tool, this technique can be used to create original articles which can then be used for posting online or any other purpose without being identified as a duplicate content.
SpinnerChief works in a similar way by polling its huge Cloud Thesaurus for the statistically best synonym. As the Cloud Thesaurus grows, so it gets better and better at synonym replacement. The cloud thesaurus supports more than 20 languages, including German, French, Spanish, Italian, Swedish and Portuguese (both Brazil and Portugal), Dutch, Indonesian, Greek, etc...
When you integrate Perfect Tense with WordAi, Perfect Tense will check any text you spin for grammatical errors. Perfect Tense will then add those spelling and grammatical errors as synonyms. This means that your spintax will be more unique and more readable. When using Perfect Tense with WordAi, your spun content will often end up even higher quality than the original.

QuillBot is a state-of-the-art paraphrasing tool. It is the best article rewriter available, and can completely paraphrase an entire article for free. Simply input a sentence, and hit the "Quill It" button. QuillBot will then rephrase the content while maintaining the original meaning. You can then click on any of the words or phrases to have a drop down thesaurus appear which can then provide further edits in order to optimize your sentence. It is the best article spinner out there. We will even provide statistics to how fluent the sentences are, and how much they have changed. QuillBot can also function as a grammar checker and fluency enhancer. In addition to this, it can provide you with creative suggestions on your sentences. We labeled the software as a "smart thesaurus for sentences" or a full-sentence thesaurus. QuillBot underlying technology uses complete machine learning. This means that when you interact with the website, you are providing data that will be used to improve QuillBot's proficiency. This also means that the version you are using will be the worst version of the model, and that it will constantly improve. Users have been uitilizing QuillBot for a variety of purposes. They use QuillBot as an SEO optimizer tool, in order to improve their writing, or simply get over writers block. The language that QuillBot produces is natural, and will improve overtime as well. Our mission is to achieve human-level paraphrasing. Once we achieve this task, we will aim to produce language in particular linguistic styles or degrees of sophistication. We will even allow users to control the degree of permutation that the paraphrasing tool produces. This will give users complete control over QuillBot and the ability to manipulate language to meet their needs. While our goals our ambitious, we see a clear path forward towards achieving them!

Imo it is not possible for google to detect properly spun content, it is not worth computing power it requires. They can do this using ngrams for example, but it is uses a lot of queries. And for example article spinner I coded beats this algo, so google cant detect that the content is spun. Manual spinning is also good but it takes more than 30 minutes per article.