Free spreadsheet apps are a cool idea, as long as you’re comfortable with their limitations. Many are ad-supported, for instance, so expect part of your screen to be trying to sell you something. Upgrading to the paid version (when available) might be worth the ad relief and extra features you’ll get in return.
Also, working with a spreadsheet on any smartphone screen—even some of the bigger devices available now—can be a squinty affair, best for viewing or extremely basic data entry. Of the five mobile spreadsheet apps I tested, the best made it surprisingly easy to work with the data on a small screen.
Free Spreadsheet

Free Spreadsheet is ad-supported, but you have enough room to enter and view formulas.
Free Spreadsheet is ad-supported. And while I understand that everyone has to make money, I still found the ads that run across the bottom of this iOS app a bit distracting.
Overall, though, Free Spreadsheet is easy enough to use. Its layout is roomy, so even on the small screen of my iPhone (which feels even smaller now compared to the new iPhone 6 models) I didn’t have to squint to see the values of each cell—though, of course, the number of cells you can view on an iPhone screen is limited. l also like how the touchscreen interface works when inputting data.
Saving files to your iPhone is easy, but transferring them to a computer via the built-in Wi-Fi sharing didn’t work well for me. My computer recognized them only as image files, and not as spreadsheets that I could open in Excel.
For basic number crunching on an iOS device, Free Spreadsheet does the job. But I wouldn’t do anything more than that on this app; it would be way too tedious.
Documents To Go

DocsToGo offers a desktop-like spreadsheet experience on the small screen of a smartphone.
If you opt for the free version of Documents To Go, you’ll also be faced with ads. Upgrading to one of the paid options for this suite will eliminate those – but that’s not the only reason I’d suggest forking over $6.99 (for Cloud access) or $16.99 (for the Premium Pack) on your iOS device, or $14.99 (Premium) on your Android.
These paid apps let you open, view, and edit Microsoft Office files (Word, Excel, and PowerPoint) that you have stored in accounts such as Box, Google Drive, Dropbox, OneDrive, and more.
If you stick with the free version, your access is more limited, but you still have Documents To Go’s slick interface, which allows you to work with the most detailed spreadsheets with ease.
Switching between worksheets is easy, as is entering numbers and formulas. At times, I found Documents To Go a little too busy on my small iPhone screen, but that’s a worthy trade-off for the power of this portable spreadsheet tool.
Google Sheets

Google Sheets features a mobile-friendly interface, making it easy to view your various spreadsheets.
Google Sheets lacks the slick interface of Documents To Go, which somehow manages to make a spreadsheet on your iPhone look like a spreadsheet on your PC—while still remaining readable. But if you can live without that sort of flash, Google Sheets has a lot to offer.
It’s free and free of ads, and it integrates directly with your Google Drive account. Any spreadsheets you have stored there are automatically accessible from your Android or iOS device. (Google Sheets works on desktops, too.)
I like how easy it is to view and edit basic spreadsheets, and how Google Sheets saves files that can be accessed on a desktop with Microsoft Excel.
As a Google Drive user, I especially like the tight integration with Google Drive: All of my spreadsheets were readily available, right from the comfort of my iPhone. But if you rely on another cloud service, Documents to Go might be the better option than Google Sheets.
Simple Spreadsheet

Simple Spreadsheet’s interface won’t wow you with its design, but the app is easy to use.
Android users looking for a cheap and easy spreadsheet app will appreciate Simple Spreadsheet. Available in free (with ads) or paid ($2.00) versions, Simple Spreadsheet lets you create and edit basic spreadsheets on your Android device.
The interface is definitely more simple than slick, lacking the desktop-like design of Documents To Go and even the mobile-friendly look of Google Sheets. Still, Simple Spreadsheet is perfectly functional, allowing you to enter numbers and formulas with ease.
Sheet2

Sheet2 lets you navigate the app through its nicely-designed tools across the bottom of the screen.
I was pleasantly surprised by Sheet2. This iOS-only app proved impressive when used to create and edit spreadsheets, even on a small iPhone screen.
Sheet2 links to various cloud-based services, including Box, Dropbox, Google Drive, and others, allowing you access to your stored spreadsheets.
Opening spreadsheets stored in my Google Drive account was a touch slow, but once Sheet2 accessed my files, it displayed them beautifully on the small screen. Its editing tools are nicely laid out across the bottom of the screen, and I like how you can scroll through the various worksheets of a single spreadsheet as if they were images.
Sheet2 lets you save spreadsheets in .xls or .xlsx formats, and you can share them via email. The spreadsheets I created on my phone opened seamlessly on my desktop in Excel, with no data lost. At $3.99, Sheet2 is more expensive than its free rivals, but its feature set is a step above them, too.