I found the feature momentum in my previous dell Synaptics trackpad, where a cursor keeps moving until I stop. I actually found that feature very useful to reach every corner of screen very quickly. But I can't find it in my Asus K556U. It has a software "Asus Gesture", which doesn't provide me this "momentum" feature. Can I get rid of Asus Gesture and install Synaptics trackpad instead? Or is their any other way I could get that feature?
For Synaptic touchpads with OEM software there are Registry settings, e.g HKLM/SOFTWARE/Synaptics/SynTPPlugins/MomentumMotion. Set it (1) to enable momentum, which should now appear in the pad configuration dialog. If you need to install Syanptic (as opposed to generic Windows) drivers, check the Asus site, or try one from Lenovo.
Similarly, Elan touchpads have a key, HKEY_CURRENT_USER\Software\Elantech\SmartPad, but you also may need to install OEM drivers.
N.B. A number of users have mentioned that after installing OEM drivers, they were overwritten on the next Windows update, so keep the driver installation files handy, or (try to) prevent MS from updating drivers along with Windows.