YAOP – Yet Another Object Pooler is a free Unity3D tool/package.
YAOP is what I personally use in my own game development projects. It is designed to be fast, lean and simple to use.
Some features include:
– Automatic Growth
– Dynamic Shrink To Fit
– Default State of Objects
– Pooled as child

Completely free to use, with more features and fixes coming in the future.
LINK: Yet Another Object Pooler

Do give it a try and leave a comment on how it works for you. Cheers mate!

Source: itch.io