It is not fired off very often, mostly because people go to all lengths to stop the ultimate happening but also because he only has a +1 to grow, starts at a measly 3 loyalty and often needs to fire off a couple of -2 effects en route so as to remain alive
At some point, I saw and built a Grixis Dragonstorm Commander deck with cheap ramp spells, tutors, and fast mana to build up into a large Dragonstorm, and swing for the win with hasty dragons thanks to Dragonlord Kolaghan or a convoluted combo involving Worldgorger Dragon and Animate Dead, making it one of the funniest decks Ive ever played with
The leaders that dominated all had search, draw, or selection tools that made their game plan reliable
Both of those apps also offer fantastic tutorials, letting you learn the basics of each game, and they both furnish players with a bunch of free decks meaning if youre reading this and havent tried, theyre worth the download, even if youve never cracked open a booster pack in your life