I like having all of my email addresses in one place, easy to access, easy to use and understand. Not only all my email but also all of my calendars in one. The calendars are customizable with color. You can use quick add to add an appointment quickly or add a task. a note, a reminder and you can convert a task to an appointment. You can create checklists. One very nice thing is that it offers backup. However frequently you desire you can create a backup and send it to email. I have yet to do a restore though so I can't yet testify to that. I find myself using this over Calendar and other apps I've tried.