Hello,
first of all I want to say nice to be here and thank you for this great free software. I’ve already used the forum search, but couldn’t find an answer to my question, so I decided to ask directly.
I work on Windows at home. In the office or when I’m on the go with a Macbook. Is it possible to work on / or have access to a project that is in the cloud with different systems / with or without the premium plan?
Many thanks for the answer 
As long as you are logged in and your project is saved to gdevelop cloud storage you should be able to access it anywhere, otherwise i dont see a point in the whole cloud storage thing.
Yep, you can use GDevelop cloud storage to access your project from anywhere with your GDevelop account. Although you do not need a subscription, I think that without one you have a cap of around 10 projects. All online services are capped sadly as each usage of those takes money out of the GDevelop team’s pocket… (Our host, AWS, bills based on usage)
