The task of simulation is often complicated for which many naive users often seek for relatively easier solutions. In many cases, simulations are done without any visual output which makes them non-attractive. In this paper, we present ViSim; a new simulation tool that has a user-friendly graphical interface. ViSim could be useful for researchers, students, teachers in their works, and for the demonstration of various wireless network scenarios on computer screen. It could make the task of simulation more exciting and enhance the interest of the users without going into complex command-only text interface. ViSim is not a simulation engine rather it calls ns-2 simulations in the background and makes the task easy for the users to visualize the simulation in Windows environment. Though ViSim is mainly a simulation demonstration tool, any user with the knowledge of ns-2 and Tcl scripting is also allowed to do necessary modifications and quick configurations for any other MANET routing scenario. Using our simulation tool, we measured the performances of several Mobile Ad-hoc Network (MANET) routing protocols. In this paper, we present the performance analysis of three prominent MANET routing protocols; DSDV, DSR, and AODV using our tool. The details of various features of ViSim, brief descriptions of the selected routing protocols and their comparisons, details about the performed experiments, and the gained results are presented in this work.