yeses.io

Most approval work is not the reviewing. It is the chasing: the follow-up message, the "did you see this?", the meeting booked to get three people to say yes to something they already agreed with.

yeses.io takes that over. You send a file, a page or a decision for review once. Reviewers open an individual link, with no account, no signup and no password, and give one of two answers: approve, or request changes. If a reviewer goes quiet, yeses.io follows up on its own, a reminder every two business days, up to three times per review. Approval flows can run in multiple stages, with custom response windows per stage.

What comes back is a record rather than a thread. Every decision is attached to a person, a timestamp and a specific version, and an approval given against a file that has since changed is flagged as stale. Slack notifications are available on paid plans. Reviewers are unlimited on every plan, including the free one.