You can find the default materials and programs in the builtins folder. If you are using sprites make a copy of the sprite material and fp/vp programs then set the copy of the material to be set to the new copies of the fragment program/vertex program and not old. Then in the vp you can set
attribute mediump vec4 position;
to
attribute highp vec4 position;
While you’re at it you can set a DIFFUSE_TEXTURE sampler to the material samplers and set it up how you want.
If you don’t modify the fp you don’t need a custom copy of it.
You might need highp set on other values too. Test and see.