Astroversary
That one app that reminds you of birthdays and the presents you want to gift, so you don't forget them.
... when you have them. No Need to scribble them down, just add them to the person you want.
Add all birthdays of your friends and family.
So it's easy to add all your contacts.
Don't ever forget a birthday again. Just add the person and the date and you will be reminded.
Add widgets to your homescreen to keep an eye on the next birthdays.