I've used Jumpstart Rails and I recommend it. It's made by Chris Oliver from GoRails. It has a ton of features built in like auth, payments, I18n, notifications, user impersonation, and more.
Disclaimer: It is a paid software, and I am not affiliated with Jumpstart or GoRails.
Disclaimer: It is a paid software, and I am not affiliated with Jumpstart or GoRails.
[0] https://jumpstartrails.com/