Careful if you're updating on Android 4.4 KitKat, though ...
A quick heads up for those of you rocking SwiftKey — version 4.3.1 is now available. The big strokes for the changelog are bugfixes — the $ sign is back for non-English keyboards — and the option to put the numeric keypad on either the left- or right-hand side.
If you're updating on an Android 4.4 KitKat device, however, you'll need to look out for a gremlin. After updating, the Google Keyboard will again become the default — and SwiftKey won't appear in the list of default options. Two options to fix that: Hop into the SwiftKey app, and that appears to reset it, or choose "Select Input Method" from Settings>Language&Input>Default. Let's hope that gets sorted out right quick.
Swiftkey's got a more thorough changelog at the link below.
More: Swiftkey blog