I'm a fan of MS Excel _ my apologies for those who have issues with Microsoft _ because I find its powerful calculations are easy to manipulate to help me better understand my finances. It doesn't really matter though which spreadsheeting package you use so long as you are able to calculate your amounts effectively. There are commercial budgeting worksheets available but if you want to create your own its a simple process.
The biggest advantage of Virtual Envelopes is that your money is safe in a banking institution instead of cash in envelopes in your house. Just imagine if you hade robbery, fire, or just plain old forgot where you put that cash envelope with your rent payment. Not a fun time trying to recover that!