SDKBOX started life as a tool that made integrating 3rd party SDKs such as Google Analytics or Google/Apple IAP into Cocos2d-x applications easy. It was just recently spun out from under the Cocos2d-x project by parent company Chukong. This move seems to be in advance of adding support for other engines, namely Unreal and Unity. Right now however the implementation for both engines is minimal, limited to just the In-App Purchases module. I assume in time more plugins will be brought over to the other engines.
From the above linked article:
Asked why the company did this, Zhao said in an email, “By being a standalone company we can cover a much broader (fully half) portion of the market. SDK fatigue is an efficiency drain for all mobile developers, regardless of the engine they are using. By defining the problem we are working on, rather than the engine we are working with, we can serve game developers impartially.”
SDKBOX has also begun supporting rival game engines from Unity Technologies and Epic Games with its 2.0 update. And earlier this month, the SDKBOX in-app purchase controller was approved for sale and listed in the Unity Asset Store.
Haozhi Chen, CEO of Chukong Technologies, said in a statement, “Spinning off SDKBOX was the next logical step for scaling the business within the games industry. This move provides more autonomy for SDKBOX to support additional engines and grow market share in the live operations technology market for games. Additionally, the new company will have dedicated financial and strategic support from Chukong, and we’re looking forward to the future growth of this sector for our overall business.”