If you're a financial analyst, Excel for iPad won't tempt you away from your four-monitor desktop, with your Bloomberg or Dow Jones feed in one monitor and Excel running in the other three. But if you're just doing simple business projections or keeping track of your finances, Excel for iPad gets the job done more elegantly and efficiently than anything else on a tablet. You can download the app for free, but that only lets you view documents. If you want to unlock the full document editing features of Excel for iPad – or its suite-mates, Word for iPad and PowerPoint for iPad – you'll need a subscription to Office 365, which typically costs £80 for consumers.
What's there, and what's not
Microsoft did an impressive job of shoehorning the gigantic industrial plant of desktop Excel into the narrow dimensions of a tablet. You get all the essential desktop options for formatting, sorting, and filtering; adding and removing columns and rows; a generous selection of charting styles, each with a wide range of optional variations; a large variety of functions in all the categories supported by desktop Excel; and options for showing or hiding gridlines and freezing panes for easy navigation. I've grown addicted to the single-cell charts that Excel calls Sparklines, and the iPad version includes them as well.
What you don't get on the iPad are macros, data imported from external files, and advanced sorting features like "slicers" and timelines (these aren't in the Mac version of Excel either). You can view and delete comments, but you can't add or edit them. You can view existing pivot tables, but you can't change or re-pivot them, and you won't be able to use advanced data-managing add-ins.
I was impressed by Excel's smooth handling of the giant worksheet I use for testing. It opened instantly, but it displayed an "Unsupported Content" message. Another message told me the content in question was the split-window feature in desktop Excel. I could only edit a duplicate of the worksheet that lacked the unsupported content. This is an inconvenience you may or may not be willing to live with, because it left me with two copies of the worksheet, one editable on the iPad, and one that wasn't. Both the original (uneditable) copy and the duplicate copy displayed all the charts accurately, however.
My major complaint was the lack of scroll bars that would let me navigate the huge worksheet without swiping. Pivot tables appeared as static tables because the iPad version doesn't support pivot tables, but at least I could see them in the state they were in when I last worked with them, and they weren't removed when I made the duplicate copy.
Excel by the Numbers
Excel's closest rival on the iPad is Apple's Numbers, but Excel includes many more functions, and it feels more efficiently designed. Numbers includes a dynamic charting feature that shows a chart changing its appearance as you drag a slider along one of its axes, but in most other ways, Excel outclasses Numbers in its feature set.
Both Numbers and Excel include a custom keyboard for numeric and formula entry. The custom keyboard in Numbers changes dynamically if you're typing a date, formula, or text, but the Excel keyboard gives you most of what you need in a single layout.
Click the 123 icon at the upper right of the standard on-screen keyboard in Excel (not the familiar button showing ".?123" at the lower left), and the custom keyboard appears, with a full-sized number pad on the right and an inverted-T set of arrow keys in the middle, as on a full-sized keyboard. On the left are common symbols used in formulas – percent, caret, sigma, and others. It's the closest you'll get to a full-scale keyboard on a tablet, and it's more convenient than the limited set of keys on a standard add-on keyboard.
As with other virtual keyboards in iOS or OS X, when you hold down a key in Excel's formula keyboard, a menu of alternate symbols pops up, so if you hold down the dollar-sign key, you'll get a menu of other currency symbols; if you hold down a parenthesis key, you'll get a menu of square and curly brackets. Microsoft signals these keys with a green wedge in the upper right corner of the virtual key cap.
I'd like to see Excel add some features that break the iPad norm but add convenience. Scroll bars would be top of the list, but I'd also like to see a few other features from the desktop version added to the interface, such as a ribbon-based option to transpose data from the target to the source when pasting from one to the other.
If you don't have an Office 365 subscription and aren't sure if spreadsheets on the tablet are for you, you should still download the app and give it a try. You'll find it lets you change the way rows and columns are sorted, but that you can't save your changes. Chances are that, if you're a committed user of spreadsheets, you're likely to end up shelling out for access to the full functionality. Excel for iPad is one very impressive app.