This appears to be a shell script to deploy sshuttle to a DO droplet.
I've seen this sort of thing be helpful when the software is cumbersome to install and/or use. But, looking at the sshuttle docs, it doesn't look terribly complicated.
I've not used sshuttle myself, so maybe I'm missing something? Is it difficult to install or use? Honestly curious what problem this shell script is addressing.