Referring to cells on a different tab

Is it possible to refer to cells on a different tab in a formula?

This is not supported right now. You can add a custom function that lets you access cells in other tabs. You could call this function then from your formula cell. However, this is only a half solution because there is no dependency mechanism. So when the value in the other tab changes, the referring cell is not updated. We will add support this in future versions but I can't give a timeframe just yet. Stefan