Uni Cache for Unity that allows to store you downloaded images/text/etc to disk for later use.it includes two demo version.
Simple Cache System without versioning and Versioning Cache system moreover you can implement your own cache system all source code is included.
Documentation
Cache management system for Unity3D.
This library supports PC/Mac/iOS/Android/WebGL/Windows Store App/etc.
This library is free and opensource on GitHub. More info, supports and sourcecodes, see
Github