Tuner studio works in place of the outdated Megatune. Tunerstudio is more user friendly with slide bars and graphs.
There are two versions. The free version which still lets you tune your car
The register version has a couple more options
The main one is
VE Analyze Live
Which tunes the VE table while you drive and it works pretty well.
Website with more info
http://www.efianalytics.com/TunerStudio/
I do have the registered version on my computer and it is nice.
You can get by without it and use the free version to take control of the MS and tune it yourself. There is nothing wrong with going with the free version. It is a GREAT improvement over megatune.