Allows you to add custom widget content on a post-by-post basis from the edit post screen.
A simple plugin that allows you to create multiple "regions" inside widget areas which the content for that region can be customized on a per-post basis. Supports adding shortcodes and HTML inside the contents. The plugin is compatible with Polylang plugin and shows the snippet admin screen based on the language.
Based on the My Snippets plugin from Justin Tadlock, this plugin has the additional feature that you can have multiple snippets on each page.