Now, not only can you create and edit a document in google drive on your iOS device but you can also create a new one and edit a SREADSHEET inside the google drive app for iOS!
The spreadsheet looks great, you have many of the same functions that you would if you were using a desktop browser.
Another fancy feature of the iOS spreadsheet you won't notice until you've added ,any sheets to tout new spreadsheet is this. When the sheets start piling up and you need to get access to one of the many sheets simply slide the sheets down and they will adjust to your screen a so you can get to that 15th sheet you made!
I've not yet seen a drop down option for choosing Formulas but you can manually enter in a formula for a range and get the results