Today, Microsoft released the June 2017 update of Office for Android to Insiders. The new apps, which are build 16.0.8229.1001, focus on improvements to Excel and PowerPoint.
In Excel, you'll now be able to open files that have Dialog sheets; indeed, adding the ability to open more files seems to be a consistent goal for the Office team. You'll also find a new numeric keypad, which you'll be able to switch to quickly and easily.
Over in PowerPoint, users can now "add, change, delete, or reply to comments in a presentation on your device." You can learn more about that here. There are no features listed in the changelog for Word.
If you're an Office Insider, these updates should now be available through the Google Play Store. If not, then you should see the updates within a couple of weeks time. You can download the Office for Android apps from the following links: