Add a Plugin from a Non-paid Appian community site?

I do not really understand your question. Please elaborate.

Hi Stefan,

currently, I have been using a Non-paid Appian Community Edition Site for application development for my practice. I have developed a plugin which I want to add that plugin into the Appian market. But I am unable to do find the gateway to add that.

OK. Check this: docs.appian.com/.../component-review-process.html

You'd have to contact Appian Support / Community Edition Support and ask them to deploy it for you (if it's possible for them). 

This raises a good point as I feel it's a missed opportunity that they don't provide some easy way to self-deploy under-development plugins on our Community Edition sites, since then they could very easily function as a true alternative to local installations, since they'd be able to handle the "plug-in development" use case. 

For instance, on my locked-down corporate computer, I'd never be able to install all the software necessary to do a local Appian install, so if I'm ever faced with the prospect of needing to develop a novel plug-in, I'll be stuck.

You'd have to contact Appian Support / Community Edition Support and ask them to deploy it for you (if it's possible for them). 

This raises a good point as I feel it's a missed opportunity that they don't provide some easy way to self-deploy under-development plugins on our Community Edition sites, since then they could very easily function as a true alternative to local installations, since they'd be able to handle the "plug-in development" use case. 

For instance, on my locked-down corporate computer, I'd never be able to install all the software necessary to do a local Appian install, so if I'm ever faced with the prospect of needing to develop a novel plug-in, I'll be stuck.