From personal experience Spin Rewriter is the best! like I still use it today. Its so easy to use (Just copy paste and the program do everything) Because of this tool I managed to schedule content and articles for 3 years, do you know how much time and money I’ve saved?!?! A LOT!!! Also i high recommend you pick their mothly plan if you are still in doubt
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.
2. Show Off Your Singularity - In my previous posts, I have discussed the value of being distinct from others in your business. You must promote your singularity. What's it about YOU that will bring your audience for you? Among the greatest mistakes you can make is attempting to duplicate someone in your business. Although, they may become successful, you're not giving your target audience reasons to pick your services over theirs. That is why it is essential to reveal your audience why you're distinct, and be consistent with your singularity.