Of course, even if Gametable was made to enable you to play roleplaying games via internet, nothing prevents you to use it for your wargames.
First of all, it is possible to play online the skirmishes wargames that it would be possible for you to play with figures on a table. Either historical games (with Fire & Steel rules, for example) or fantasy or science fiction games (like Warhammer 40K, for exemple). If each player has the rules and since the dice rolls results are visible on line, there is no problem to set up this kind of wargames. Using Gametable this way is not very different from using it in roleplaying games.
Then, for those who use mass battle rules, playing with many units, it is also possible to use Gametable to record campaign data on a map, playing battles with figures on a table.
The major advantage of using Gametable this way, is the ability to play the campaign moves between the wargame meetings, which limits drastically the time lost during game sessions. If, moreover, you have a referee, he can carry out the moves and communicate to the players only the elements which are visible to them. The use of the private maps enabling the application of "fog of war" to player's moves. For full application of fog of war, the umpire can move and manage all the units on his private map, revealing what is visible to a player on the public map, take a snapshot and send the snapshot to the player (even with errors added to simulate bad reporting from subordinates).
And if you use multi-level maps, scouting parties can discover places where terrain itself is different of what it was supposed to be (a frequent occurence in times before reliable survey maps).
Finally, the possibility of recording the unit's information on the token labels enormously facilitates the management of a campaign (in particular the management of provisions, ammunitions, straggling...). Each unit can have any number of campaign informations attached to it.