VPNs that do no encrypt data?

Yes!
You can see the report on Android (free and not free) VPNs here:
https://research.csiro.au/ng/wp-content/uploads/sites/106/2016/08/paper-1.pdf
And an article summarizing it here:
https://www.techgig.com/tech-news/editors-pick/Avoid-these-10-insecure-VPN-apps-on-Android-88546?mailer_id=2888&utm_source=TG_batch&utm_medium=email&utm_campaign=digest_news_2017-01-26&etoken=cGZzaWx2YUBnbWFpbC5jb20=&activity_name=MjIwNzcw&dt=&auto_login=lKaUjJKbhWOnk7@@OkG6EkpNlR0eASYJcXXFUV1dlR0eASYJWWHhWV15YWFxy&src_type=autoLogin