This is a paid asset, but now you can download Gradient, Transition and Dissolve Shader Pack Free.
Detail this asset from Unity Store: Original Link
Gradient, Transition and Dissolve Shader Pack v1.3 (Latest version)
This shader pack contains every you need for smooth image or even scene transition.
NEW NEW NEW
Shader Pack grew even stronger. The package now contains CAMERA TRANSITIONS for smooth blending between multiple cameras in the scene. Use all blend effects for camera blending. Sample scene included.
NEW NEW NEW
17 Image Transition Shader
Add soft blend between two pictures to your project with 17 unique shaders. Full source included!.
Gradient Shaders
Add beautiful, adjustable color gradients to your project: linear, radial, diagonal, star, polar and bilinear color gradients. Freely customizable colors and angles. Choose between solo gradient or texture with gradient overlay.
Demo scene with animated sunrise gradient included.
Dissolve Gradient Shaders
These shaders allow you to transition between 2 textures or dissolve a single texture. The dissolve is controlled via a grayscale bitmap. Combine the supplied gradients or draw your own for your very special gradients. Demo scene and full source included!
Fire Dissolve Shaders
Dissolve a texture with a fire, acid or energy/electricity effect. These beautiful shaders use the dissolving technique with a configurable Color Ramp. Draw your own ramp for your own special effect. Demo scene and full source included!
Online Web Demo
For a demo, just start the menu scene. If there are any problems with this package, feel free to ask for support in the comment section of the asset store or send me a mail.