Alarm Clock Xtreme Free
Alarm Clock Xtreme Free is my favorite alarm App by far because it allows a high degree of customization, yet it remains simple. Each time you set an alarm, it will still be there in the future to reactivate, unless you choose to delete it. The numerous setting options include being able to automatically repeat them on given days of the week and labeling them if you wish - for example: Work Days, Medicine Reminder, various routine tasks you may have, whatever! You can set Snooze options and Sound options. There are more advanced settings as well. Alarm Clock Xtreme Free is a free App to download... search for it at the Play Store. (There is also a stopwatch available with its own great options.)
Assistive Light in WIDGETS! I didn't discover these for a while, dazzled as I was by all the App icons. Okay: When you touch the Apps button (lower right hand on any main screen), it takes you to all the pre-installed Apps. But Hey! There are two tabs at the top when you get there, Apps and Widgets! The Assistive Light Widget is the one I'm most grateful for. Consider its obvious usefulness as a kind of virtual flashlight at hand - no extra gear or batteries to be concerned with. It also makes a fantastic reading light at night. I just turn it on, prop it on the pillow, and read... 'love not having to get up to turn a lamp off, and it's a superior reading light to what the lamp provides anyway!
Google Calendar is a truly wonderful program (with advanced capabilities worth exploring if you have complex needs) and the Calendar App brings it all right to your phone. I've had it set up on my laptop for a long time. The ability to customize automatic email reminders and repeats (birthdays/anniversaries, for example) is priceless. I also use it to note phone calls or follow-ups that should happen at some point - say it's Saturday and I think of a call that can't be made until Tuesday, or want to be sure something happened by the time someone said it would. The App for the Galaxy SIII is pre-installed and syncs with your other devices, so whatever you enter on your phone appears elsewhere as well. Bonus: there's a Calendar Widget, too, that lists upcoming events on your phone screen.