Microsoft's app stores add the first universal apps for Windows and Windows Phone

Ever want to pay one price for a game - and then play that game on your phone, tablet, and PC? Well, now you can. Microsoft has approved the first universal apps for Windows and Windows Phone.

As spotted by PC World, the first universal apps (two of them to be exact) have launched. They are actually paid apps that cost $4.99 each. One is called Halo: Spartan Assault, which is from Microsoft, and the other is 17-Bit's Skulls of the Shogun. You can download both apps starting today either through the Windows Store or Windows Phone Store.

Technically, Microsoft has also re-purposed a few existing and free games so that they are now universal apps, as noted by WPCentral. Those games include Wordament, Hexic, Mahjong, Minesweeper, and Solitaire. When apps become universal, your saved achievements and levels will auto-sync across all your Windows devices and computers.

READ: Microsoft unveils Windows 8.1 Update with universal apps

Microsoft first announced universal apps were coming when it unveiled Windows 8.1 Update at the Build 2014 developer conference. Universal apps are a big deal for developers, as it means their content will be accessible on every Microsoft platform instead of just one, but it also means consumers will only have to pay once to use an app anywhere and everywhere.

Keep in mind you will need to buy the Windows version of Halo: Spartan Assault separately from the Xbox One version, if you desire. That's because universal apps aren't available for Microsoft's gaming console. They will be eventually though, according to PC World. There's just no word yet on when that'll happen.

Note - Thus far, Windows Store listings do not specify which apps are universal Windows Phone Store listings however provide the following notice: “Made for Windows Phones and Windows PCs".