The Vulkan graphics API is a big deal for mobile developers, since its direct GPU access allows for complex graphics to be rendered with a considerably lower hit to the processor, and thus a lower overhead on the hardware and battery life. A few devices like the SHIELD family and Samsung's 7 series already supported Vulkan several months ago, but Nougat now features full support for all updated Android 7.0 devices. Developer Super Evil Megacorp, which turned heads last year with its Vainglory mobile MOBA, now has a beta version that uses the Vulkan API.
This release of the League of Legends-style strategy game is more or less the same as the earlier edition, including full access to the popular multiplayer combat. Super Evil Megacorp (nope, that's not getting any less dumb) says that this Vulkan-enabled version runs 30% more efficiently on supported hardware, resulting in better battery life, faster controls, and higher framerates.
This version is technically compatible with Android 4.1 or higher, just like the standard Vainglory. But of course, your phone or tablet will need to support the Vulkan API in order to actually run the app. Vainglory is free-to-play with in-app purchases that go up to $100. Note that the Vulkan version is in beta, so it may be more unstable than the standard Play Store release.