Twitter has just announced the availability of sorely-needed updates for its Android and iOS clients that appear to offer significant tweaks across the board. On the Android side, the marquee feature has to be Android 4.0 optimization — including hardware graphics acceleration — while the iOS products goes a little deeper with better copy / paste support, a direct message UI redesign, font settings, and more. Thankfully, we can confirm that the Android version is feeling far snappier on our Galaxy Nexus than the build that it replaces, and seems to fix the all-too-common bug of the timeline "bouncing back" after flicking to scroll.

Along with the updates, Twitter has also launched apps for both the Kindle Fire and Nook Tablet (and Nook Color) — since all of these are Android tablets, it should more or less be a matter of getting the clients submitted to the appropriate app stores. The Fire version is available now, while the Nook one will launch on Thursday, the 23rd.