What is the best "Daily Planner" app for iPhone?

This is a good question. My issues is that my phone is tied to my work Lotus notes, which sucks, but I don’t have a choice. My Google Calender also goes into the iphone.

Try 2Do (my favorite) or Things.

They may scratch your itch.

Reminder
is free and can link to Google/iCloud and just gives you pings of attacks when things are due.

I’ve had various calendar programs. I find the ones for smart phones especially egregious. I hate typing on miniture keyboards. I hate so much, I’m turning in my “smart” phone and getting one that is just a telephone. I think that giving a large number of applications to a phone is a waste of time and courting with danger by putting “all of your eggs in one basket”.
When the phone fails (as it inevitably will) you lose much more than phone service.

I prefer a Daytimer where I can write my thought and appointments immediately. I’ve been using them for twenty years and never had a failure where all my data was lost. I can’t say the same for my computers or smart phones.