Five stars from

1. entity check - owner traces back to real person, freely found online, one star
2. support - open source github, where issues can be raised, two stars
3. security - no real issues found, good suggestions*, three stars :
https://github.com/nunoarruda/auto-save-html

* including one via email to the owner, who posted it to the "issues" himself. Good sign!

very useful for me

It works well! Automatically saves pages whose URL matches a regular expression. Thanks!