This app was mentioned in 10 comments, with an average of 2.10 upvotes
I track mine with 17track, it can track parcels from multiple delivery companies. Also has a nice widget to keep an eye on your tracked parcels.
To any android(not sure if it has an iOS version) owners, I found a free and ad-free tracking app with widgets that seems pretty good.
Supports GLS and I saw FedEx in the list too
Hope this helps
I'm using 17Track ,worked great so far.