I use this free shell host all the time. It's great and always online and is fast and the owner is very kind (you can simply e-mail him to request a package to be installed).
Check it out.
Not to be confused with freeshell.org, which is the SDF Public Access UNIX System.
They are cool but for some reason I preferred using this service rather than their's. I cannot remember why though.
These initiatives are commendable but... honestly, what do you use these free shells for? Are you allowed to host websites or other Internet services? IRC BNCs? VPNs? It's still somebody's else computer after all, not something that I trust to hold my passwords.
They seem to offer some services next to pure ssh, website included https://freeshell.de/services/
Allows me to use a UNIX-like (a linux machine) when I am at school and cannot run another OS (or simply haven't booted into one). It's very helpful.
I don't use this particular service but I do use SDF. I host a mirror of my website there, participate in community chat and bulletin board, host a gopher site, build various pieces of software, browse the web or check news/email when I'm away from my main machine and so on. SDF itself is a full blown ISP.
You could probably run your own network services on the host in the post. Temporary SSH tunnel to bypass filtering or whatever. Maybe even temporary VPN?
You can use it for whatever you'd use a server sitting in your home for.