Hi there! This post comes bearing a freebie, Advanced Pooling System, an object pooling system for your Unity3d games. Its very easy to integrate it into your project, lightweight, and is very crucial if you are developing games for mobile platforms. It greatly enhances the performance and helps you reach that 60fps bar.
The package allows you to pool all types of gameobjects and reuse them throughout your game. Pooling for particle effects and sounds is also available in Advanced Pooling System and in cases where the number of pooled items fall short you can enable the option of "expandable pool" which will allow the pool to expand itself whenever necessary.
You can get the package either from GitHub or Unity Asset Store. "Advanced Pooling System" is free for both commercial and non-commercial use, but I would still advice you to read the license terms inside the package.
There is also a space shooter demo for you to play online - Demo Link.
The documentation for this package can be found here.