Yes, I use an iPhone 5s. While many of my friends swear by their Android device, so much of what I like to use a phone for seem to work best for me in the Apple universe.
Here are my favourite apps, in no special order (I'll double asterisk my favourite/most used):
**1Password for my, uh, passwords!
**Dropbox's Carousel for photos
**Dropbox for files
**Evernote for most EVERYTHING!!
**Nozbe for Projects, Next Actions, Goals and Horizons of Focus review
Nothing fancy these apps work for me so I can live in a state of positive workflow.
What do you use?