Yes, I know, there are some such plugins. But they have some bad things:
Small and noncontrollable radius jump; if player on the ground, he doesn't jump up and other...
Therefore can somebody modify plugin
TFC Grenade Jumping (http://forums.alliedmods.net/showthread.php?p=62099), that it was possible to regulate radius and height force of jumping?
P.S.: sorry for my bad english