You can still find some grammar mistakes in the paraphrased article, but its only minimal and the resulting article is still highly readable and the uniqueness is relatively high, though I was not able to check the article rephrase in a plagiarism checker like Copyscape, although based from the result, I believe it can be used perfectly for tier 2 and tier 3 link building campaigns
Spin Rewriter integrates with almost any SEO software. This allows you to post high quality articles quickly and easily. The only drawback is that you only get something like 300 API requests every 24 hours. You can quickly burn through this if you’re doing multiple campaigns. The developer does not currently offer a plan for heavy API users but maybe they will in the future.