Do you have a data plan on your phone or will you be using wifi? I have a data plan and find it useful with the map apps to use it as a GPS when traveling in new areas.
If you use Instagram, Facebook etc, then those apps are fun and you can easily upload photos to the different platforms. I have Microsoft Office on my phone and access to my OneDrive. My local bank app, lets me pay for beef from a local farmer, while standing in the barnyard.
A white noise app, helps me to sleep, especially when traveling and there are strange noises outside.
I use the calendar app extensively. I can access my calendar on my phone, computers, Ipad etc. I enter doctor's appointments when I book them. I can set it to give me reminders.
There are many quilting apps that may or may not be useful to you.
I have a soduko app to keep me busy if I do not have a book with me when traveling.
It really depends on what you are interested in and how you plan to use your phone.