Just when I become jaded and believe that every possible app has been thought of, someone proves me wrong. In this case, the app is an email app that works quite a bit differently from those that you're used to using. Called NotaBene, this iOS app is from the folks at Fin, which is a very powerful AI service that is useful for those who need -- but can't afford -- a personal assistant.
The idea behind NotaBene is simple: it's a quick, get-the-job-done, write-only email client that you can use to send emailed notes to yourself and a short list of contacts. I don't know about you, but I am one of those people who sends himself emailed notes when I really need to remember something. It's usually easier for me to just tap out a quick note in email and send it to myself for later followup than to actually write a reminder of some sort.
NotaBene takes this to the extreme: you set up your recipients (you'll always be one of them) ahead of time, and then the app is ready to roll. Launch it, type in your note, tap send to address it to yourself, another person, or a group, and boom -- it's done. There's no typing in a subject or email address, no worries about which account your mailing it from, no concern about which signature to use, etc... Setting up the app takes a few seconds; there are no concerns about setting up mail servers.
If you have an assistant or use Fin, NotaBene can be a great way to easily assign a task for followup. For me, it's the perfect way to jot a reminder on the run. You can also record a quick voice memo or send a picture and it's all done quickly.
While I tend to discard a lot of reminder/notetaking apps, NotaBene is definitely a keeper for me. NotaBene is available on the iOS App Store for free.