Works great on the watch too.
My only issues is that there doesn't seem to be any notifications unless I have it set up wrong.
You have to go into the app to get an update which kind of defeats the purpose of the watch app.
But I am probably doing something wrong.
BTW, I think it is on sale this week.
Slice seems to work well. You can specify what stage of package progress to notify. Notifications are then standard, so appear on watch or phone based on your settings.
Look up "Delivered!" I like this app a lot. Supports multiple carriers and package, Apple Watch app to check status, notifications w/haptics when a package change its current state.
Deliveries has been around a long time, works very well, and does push notifications. Runs on my Mac, iPhone, iPad, and Apple Watch. I've looked at all the others, and still keep using Deliveries.
Deliveries works fine for this, I have it on my iMac, iPhone, iPad, Watch, and the Watch WILL prompt you.
Something else you might do, is to join the UPS, USPS, and FedEx sites, and then you can setup text and email prompts. I have all that, and, during the Christmas delivery rush, I was getting pinged and beeped and buzzed two-three times a day from the various prompts...
However I deleted that last one because it was not receiving updates quickly. It took quite a while to update.
I had a hard time finding any app that is free (for iPAD) and able to track shipping carriers from more than a dozen companies, and not limited to 3 at the same time...