Speed Boost Pro v4.0 [4.0] APK

Like Project Butter for every android version!
Install this App & you can double the speed of any Android phone.

Speed Boost aims to improve your Android experience by preventing much of the lag associated with Android by freeing up your critical CPU resources which reduces the drain on your systems speed and improves performance. Get a real Speed Boost!

Has important system toggles such as GPS (on 2.3<), bluetooth, airplane mode, brightness, and mobile data for quick, easy access. This helps save battery.
Beautiful readout of available RAM via a pie chart
List of running tasks with a beautiful animation. You don't believe me? Populate the list until it goes off the screen and scroll. Every list item flows in like butter.
You may not know it but everyday your android device stores cache files on your phone which may slow it down after extended use. Just run this every so often to improve the speed of your phone.
Has a simple one-touch widget to run a system clean from the home screen.What does Speed Boost do?

Traditional task killers only kill the running apps, which cause them to leave behind garbage data in RAM memorywhich then has to be cleared by the system, causing stutters and lag.
Speed Boost kills the running apps and then clears the garbage data left behind by the killed apps, which is what you see in the Toast message after the operation is performed.Why so simple?
It shows you just what you need to see and not anything else that will slow your phone down by displaying complicated data. Minimalist!

Google Play exclusive! Not available on iPhone app store.
Supports multi-threading for faster cache clearing, especially on the Atrix 4G, Galaxy S II, Droid 3, Droid X2, Optimus 2X, HTC Sensation, Galaxy Nexus, Atrix 2, Evo 3D, and other multi-core devices.
Now with AutoClean!Notes for AutoClean feature:

By default, AutoClean is disabled, but can be changed through settings.
File System optimizations can be opted to be ran with the AutoClean, but must be enabled through settings, accessible through Menu>AutoClean Frequency>File System Optimization.Notes on CPU controls:
Your phone needs to have root access to change CPU settings. This is a feature included in many custom roms. If you do not know what I am talking about, check out http://www.xda-developers.com/

What's in this version : (Updated : Nov 26, 2012)

added quick toggles for wifi, bluetooth, airplane mode, brightness, GPS, and mobile data
Added pie chart to display RAM memory usage
simplified optimize procedures to just one button
Added list of running apps page
Windows Phone 7 style interface
New Holo theme
miscellaneous bug fixes

Required Android O/S : 1.6+

Screenshots :