If you prefer working on a cloud IDE, you can spin up your own instance of Forem in the cloud, using GitPod.
Give it a couple of minutes to prepare the workspace. Wait for 'Awaiting port 3000... ok' message in the terminal.
You can now code, review, or just try out the project. Once you are done, simply close the tab.
You can find more information about this, in a Forem's article.