Today, Microsoft released a new build of Office for Android to Insiders on the Slow ring, bringing the build number to 16.0.8528.2001. It's a preview of the September update for the suite of apps, and it replaces build 16.0.8431.2039, which contained bug fixes and improvements.
There are a few new features in today's preview. For all three apps - including Word, Excel, and PowerPoint - malicious links are now blocked in an effort to keep users safer from malware. It's unclear why this wasn't always a feature.
In Word, real-time collaboration has been improved, as you can now see where other users are working and view their changes as they work. You can also add a blank page to a document "with just one click."
Finally, PowerPoint now has the ability to add animations to presentations, right from your mobile device.
As you can see, it's not a huge update, but there are a few things to be excited about. This build should roll out to the general public in about two weeks. You can download the Office for Android apps here, and you can also sign up for the Office Insider Program: