Today in History is a fun and easy to use app that is just jam-packed with significant information related to any given day of the year.
The application offers brief overviews of the significant events of the day with an option to research more about these events by directly linking you to Wikipedia. This app even made Rihanna's birthday interesting to me and I ended up reading about her career for about 20 minutes.
If you aren't particularly interested in celebrity birthdays, this app's main use is for significant events such as battles, treaties and other such incidents that shaped today's world.
The app links up to over 100,000 historical events. So it is easily the premier app for historical research and learning.
Compatible with iPhone, iPod touch, and iPad.