You can use Microsoft Excel Preview to open existing spreadsheets, create new ones, and of course edit them, too. You can always come back to your work exactly where you left off, since Microsoft Excel Preview recognizes which spreadsheet you've edited most recently, independent of the device you were working from.
With Microsoft Excel Preview, you can sync all your spreadsheets to both your Microsoft account and other services like Dropbox. This way, you'll never again have to worry about losing any progress you make on your work.
Microsoft Excel Preview is an excellent tool for working on spreadsheets, and it offers everything you'd expect from an official app.
Requires Android 4.4 or higher