What do you want to do with this workspace? Are you looking for a VNC controlled Linux desktop environment? Or a "codespace" with an editor and a terminal in the browser? Or an office suite? Or..?

If you just need an online office suite, you can go for Collabora Office. It has some nice integrations, collaborative editing etc. Not sure about an iPad app...

As others mentioned it would to know what you plan to use the workspace for.

If it's general configuration management and coding (text editing) an alternative to something like guacamole/rdp/vnc would be to use VsCode remotely over SSH. This lets you run code's UI on a local machine but open and operate on remote files with little overhead. The other option is always ssh + tmux + vim, which is really lightweight, but probably harder to learn.

While remote desktop solutions work (like guacamole) they can introduce a fair amount of input latency which can be awkward.

Perhaps CryptPad fits your needs. It's an open-source privacy-aware collaborative office suite and storage solution. It's end-to-end encrypted, so even if it gets hacked no usable information is leaked.

Something like Guacamole could be a nice fit. Additionally, you need a virtual PC to connect to, Guacamole is just the proxy.

As others have mentioned, workspace is too vaguely defined for good answers. FWIW, I use the Blink Shell app on iOS to ssh into my server and/or computers from my iPad for my command line workspace. I also use my iPad to access/use many of the services I’m self hosting.

If you’re looking for a gui/DE, then something like guacamole would suit you better.