CudekAI bundles many writing utilities in one place. You can check whether text looks AI-generated, rewrite AI text to sound more natural, paraphrase content, fix grammar and scan for plagiarism.
It also includes an AI writer, citation generator, AI chat and a research assistant. The site says no credit card is needed to begin, which makes it easy to try. Keep in mind that AI detectors are not always accurate, so use results as a guide rather than proof.