In looking at some different ways to reduce expenses recently, I considered getting rid of my smartphone (the iPhone 4) and its accompanying monthly data plan. It quickly became apparent that my phone was the hub of all I do in my business. I made a list of the things I do with phone and here is what I came up with. When there is a third party connected to it, I listed the app.
1. Mobile email (native mail app or Gmail for iOS).
2. Voice Calls.
3. Text Messages.
4. Taking Notes (Evernote). 
5. Setting reminders (either built in app or Evernote).
6. Twitter (Tweetbot or Twitter App).
7. Facebook. 
8. Scheduling social media posts (Hootsuite or Buffer App).
9. Adding Calendar appointments.
10. Knowing my calendar.
11. Linkedin. 
12. Alarms.
13. Phone system management (Google Voice)
14. Task Management (Producteev)
15. Voice Recognition. (Dragon Dictation)
16. News Reading (MobileRSS, Instapaper, Flipboard).
17. Composing/Editing Blog Posts (WordPress App).
18. Mind Mapping (iThoughts).
19. Payment Tracking/Processing (PayPal).
20. Managing Email Marketing (MailChimp).
Omnifocus: project planning
2Do: repeating tasks
iCal: appointments
Clay, thanks for the Comment! I have heard a lot about Omnifocus but I have not tried. I may have to give it a try sometime. I also may check out “2Do” since Evernote is not really a focused to do list manager. Thanks for the suggestions.