Hi
Tried to run ThingsBoard on a Raspberry Pi today. It claims it can run on a Pi 3, which has 1GB of RAM and however much space on your SD card (max 32GB I believe). I just happened to have a 32GB card so off I went.
Installed latest OS on a formatted SD card and followed the instructions. Once installed and running things became very, very slow indeed. So much so that the Pi was to all intent and purposes unusable. I had to physically remove power to reboot and gain any control, but once anything was "clicked" it became so slow as to be useless again.
Not a very impressive start....
However I thought perhaps I was asking too much of it with a Desktop environment enabled so I reformatted and loaded the "headless" OS with no desktop environment. Great thing about Pi's is that you can go right back to scratch in minutes... <s>
Being headless you need to login via PuTTY or whatever to interact with it.
Went through the installation again and once complete tried to login on the designated port(:8080/) using my laptop browser (Firefox) but this was unsuccessful. Firefox has a lot of security features enabled so I tried again with Microsoft Edge. Success...

I could log in using the credentials supplied when installing and I could access all the demo data I loaded too.
It appears to be running fine and it is clearly quite a powerful piece of software full of features. I will however need go through all the tutorials to figure out how to work it though. Not sure when I'll get the time but it seems to be worth the effort.
So, it seems you can host your own free server quite easily as an alternative to a 3rd party hosted version.
Regards