Developed by Maxim Yudin, the Useful Switchers application for Android enables you to quickly toggle frequently used system settings of this OS. Because the G1 smartphone doesn't come with this ability, some of these apps become vital for users who want increased productivity for their device. Useful Switchers already reached version 1
VM Heap Tool allows to change the Dalvik VM heap size to give demanding applications more heap space (thus decreasing frequency of garbage collection) to speed-up your device
Blinky is an enhancement application to the standard BLN which blinks the LEDs. It gives you an extraordinary amount of control, and can even vibrate for those who have their phone in their pocket.
Only works on the Galaxy S line
SmartLink is an open source project trying to improve the user experience for advanced usage scenarios of a mobile phone and is targeting the Android platform
TagDroid is an application that is supposed to enhance browsing on the Android mobile platform. The user can create tags using words that are of importance to him. Under each of these tags (i.e. words) the user can add the files that he associates with the tag name, so that it is easy for him to find them later