There is this new deployment tool called TOMO for Ruby on Rails apps and it is a very lightweight, easy to configure and nimble deployment tool.
I am currently using for all my Ruby on Rails apps and it has been amazing. It is easier to setup compared to Capistrano and it works very smoothly with my Digital Ocean machines. I was able to follow the documentations and able to use it without trouble and without spending too much additional time to tweak settings.
Also, as a bonus, you are able to use TOMO to deploy not only one app per machine (as instructed from its tutorial), but you can just create new user for each app and you will be able to host multiple apps in the same DO machine and using the same TOMO app for deploying your apps.
I highly recommend this tool and check out here: https://tomo-deploy.com
My current apps using TOMO:
[The image of this post is just a random picture from my photo library]