Unity Asset – See-Through System v1.8c

See-Through System is completely shader independent, so you don’t need to change your materials, shaders or touch your scene objects at all for it to work.

You can control see-through parts rendering by enabling image effects only for these parts, using depth sensitivity to fine-tune transparency toggling, using Outline or Hologram built-in shaders, or using your own shaders with help from “RenderWithShader” setting.

Despite usage of multi-camera rendering, there’s option for preserving original depth texture, so your other image effects won’t be affected by it.
Tested on Android and iOS devices.