@ all above. nice. Though I was think that A1 might not be the best for expansion, not only for the aforementioned up expansion limitation but what about to the left? and really any cell only allows expansion in 2 dimension what if I need to expand in the z axis?....
In regard to a cell phone:
It will depend on the apps you want to run. So far the feed back for the various apps I have looked up, people are unjustifiably critical that the app cannot handle their complex workbooks. Well no kidding some of my spreadsheets bring my DESKTOP to its knees, how could I reasonably expect my phone to do better. Please.
If you are expecting to drag your "office" with you on your phone, I don't think there is a phone out that will handle complex spreadsheets. There are apps out there that allow you to "dial" into your internet-connected-computer and run programs and the like. If you primarly need to look stuff up and make some additions this might be an option.
Or you will have to stick to a Laptop/notebook.