One of the more annoying aspects of owning a smartphone on a not fully-updated version of Android can be emoji. Not how they look, but which ones your device supports. If you're running an older OS version, you probably don't have the latest Unicode revision of the emoji character library, and that can lead to the infamous blank square issue.
With Android O, Google is going to solve this problem, even if in a less-than-ideal way.
A fresh version of the Android Support Library is now available to developers. This may be one of the biggest updates in quite a while, as some of the changes demand a few significant internal changes. On the plus side, there aren't very many changes that should break existing code, and most of the new features will make it worth the trouble. Here's a quick introduction to some of the new changes.
Vector Drawables and Animated Vector Drawables
Full vector support was first introduced in Android 5.0 Lollipop, allowing developers to distribute apks with easily resizable vector drawings in place of multiple images at various sizes.
At one time in history, building an app that gave a consistent experience across all (or most) versions of Android was nearly impossible without dedicating a lot of time and effort. Thanks to the Android Support Library (a.k.a. AppCompat), it's easy to use some of the most important and commonplace user interface elements on versions of Android going as far back as Donut and Éclair. A fresh update for AppCompat was just released, bringing it to v22.1, and it introduces some really big changes. The ActionBarActivity has been deprecated for a new AppCompatActivity class, several new features from Lollipop were ported back to the Support V4, and some big improvements were made for Leanback, Palette, RecyclerView, and Renderscript.