That's right, Wargaming made an excellent port of their flag game, World of Tanks for Apple iOS. It plays great and while it's easy to learn, it is very hard to master. It's worth mentioning, that the game is not an exact 1-to-1 port from PC. Game rules and the content are a little different.
First, there is only a Random Battle game mode, where during a seven minute match, two 7-player teams try to blow the other team up, or conquer "the base", whichever comes first.
Visuals are a little different, too. WoT: Blitz looks much like older PC version of WoT, but considering this game is running on iPhone or iPad, visuals are simply excellent.
Unfortunately for PC WoT players, all the progress that you've made on PC will not transfer to your tablet, mainly because there are only three Tech Trees: German, Soviet and US. The amount of available tanks is smaller, too.
World of Tanks: Blitz is free to play, just like it's PC counterpart, so in order to start playing, you don't have to pay. If you are willing to support Wargaming devs for their hard work, you can choose between buying premium tanks (which are usually faster, but weaker than their free counterparts), adding premium time (+50% to exp and rewards), or converting experience points earned by premium tanks to so called "free experience" that can be used to unlock more "free" tanks on the Tech Tree. If you don't want to pay, that's ok, you don't have to.
To sum up, you get a great quick fix PVP tank game, that looks much like it's PC counterpart, that you can play when your gaming rig is inaccessible.