Today in San Francisco, Apple kicked off its annual Worldwide Developers Conference (WWDC) with a keynote -- which brought announcements of new tools that should be of interest to mobile developers.

With iOS 9 on the horizon for this fall, Apple is adding GameplayKit, a tool to handle game logic, and ReplayKit, a tool which will allow players to edit and share gameplay videos on the fly.

These new tools will join upgraded versions of SceneKit, SpriteKit, and Metal.

The company has already posted a sample game, DemoBots, which is cross-platform and built using SpriteKit and GameplayKit in concert.

Of course, other features of the new OS version may be of interest, too -- even if they're not explicitly catered to game developers. You can find resources for the new iOS 9 developer tools on Apple's developer site.