Our examples in our PowerVR SDK include both OpenGL ES and Vulkan code, and normally make use of our PowerVR Framework.
The well-documented examples cater for everyone, from those completely new to Vulkan who want to find out how to render a triangle, right up to cutting-edge graphics techniques such as physically-based rendering (PBR) for more experienced graphics developers. Use them as a basis for your own application, or just borrow the parts you need.