Collaborate not working?

I have the pro subscription left over from the previous pricing model, and with the new craft reloaded update we are supposedly able to share an editable link with anyone, allowing them to edit without having to use Craft. However, when I send this link to my colleague, they can only edit it on a desktop, and not their phone (using android). Is this how it is designed to work (no mobile access), a bug, or is this feature isolated only to the new pricing model plans, such as Plus? does anyone know?