I recommend FBtrack, It's a must have for any Shopify store that uses Facebook ads. The app suits perfectly my needs and works very well

This app is great, I am happy about its performance. I use it with a free app to generate my product feed. All works like a charm.

Clean, easy to use, and does the job very well. It's a better alternative than some expensive apps when you only need to install backup pixels into your store

It's a great and affordable app, it allows me to add multiple facebook pixels on my store, and events firing is pretty fast. Support is also friendly and quick to respond.