What is the simplest, best option for online exercise programming for a new personal training client?

She is a busy professional who wants to be trained on her home equipment-free weights and treadmill--and wants to have exercises uploaded to her Iphone or Ipad when she works out on her own. Which programs are the most user-friendly and intuitive that will allow me to set up workout plans that she can reference for reminders? This is new territory for me!