Why can't I pay once, why subscription?
This application uses a server to track your parcels and send push notifications. It is impossible for me to support the app with ads or one time payment. Servers are quite expensive and they need to be maintained every day for smooth operation. It is really hard to keep 300+ couriers working smoothly every day.
Your parcels are tracked via the server and it is not updated real time. Therefore you may not see the real tracking data instantly. However it will eventually catch up around an hour.
You don't need to create an account. However if you want to sync your parcels across your devices, you need to create an account. Account is also necessary if you have purchased subscription and want to use the portal. iCloud account can only be used in your device. Subscribed users also has an access to their parcels via portal web site. Therefore, another credentials is needed to access the web site.
Portal is a web site that allows premium subscribers to check their parcels with their computers. You can add, delete or edit your parcels from your computer.
In order to get notifications, you must buy premium version and enable notifications from settings. If you have premium version, you can disable and enable notifications from settings to reset your notification token.
App just tries to guess the courier from tracking number. Besides couple of couriers, there is no distinct pattern to find out the courier from the tracking number. However, as you use the app, prediction will get better. Since app will give priority to your previous choices.
Unfortunately, most of the couriers don't share GPS or correct location of parcels. Sometimes they even use name of their depots. So when those places are searched, you may get incorrect or no information.
Some of the couriers use captcha and other means to restrict access to your parcel data. If courier doesn't provide public access to parcels, there is nothing we can do. Please ask those companies to open up their website for public tracking. If courier has a public web site and it is not in our list, please email the web site and example tracking number. We will try to add as soon possible.