If you need a web app to mark/count things in images, search for "image annotation" tools. I know first hand of a tool that is around since 2009 and still maintained.
I couldn't figure out how to run COSMIC so I couldn't test if the applet really supports 2D workspaces, though.
They are fraudulently trying to trick people in paying ~170 euro without any clear statement on what is their claim. Dont fall for it.
AFAIK sadly Heroku does not provide some other _free_ permanent redirect option for their *.herokuapp.com sub-domains without actually running a dyno there.
If you want to change some settings oft the device, you need to use their terrible Electron application. It's so bad, volunteers created an alternative. Even they are getting tired of Tuxedo though [2]
The device is also not repairable at all. I had an issue with my screen and they gave me a quote of ~200€+ to repair it. I'm sure I could fix it myself for a lot less, but no parts are available and no instructions.
I hope they improve, but for now I'm disillusioned and would not buy it again.
[1] https://www.phoronix.com/news/TUXEDO-Drivers-Taint-Patches
[2] https://aaronerhardt.github.io/blog/posts/tuxedo_rs_update/