Tumblr's iOS and Android apps were both updated today, with the former getting a "new discovery experience" and the latter getting a variety of updates (most notably a UI redesign). The iOS app's update adds the ability to "search tags and blogs" directly through Tumblr iOS' "discovery" section (previously you could only search by tag), making it all the easier to find that entry on Public Shaming you wanted to show mom.
The Android app, meanwhile has "fancy new post animations," and apparently it makes "images pop!" There are also a couple of bug fixes and some functionality updates -- full notes for both versions are just below, and you can snag Tumblr for iOS and Android at the links in the source. Now if you'll excuse us, we've gotta get back to reading Dear Trolls.
Update: Several of the features outlined above have been available in earlier Android updates. The search functionality, however, is completely new.