Solfege is an application thought to improve our hearing skill focused on recognizing the music scales, notes, keys and symbols that are used, as well as basic composing.
With Solfege it's possible to do plenty of interactive exercises to practice intervals, chords, scales, rhythms, among other tings. What's more, it also includes some theory and some tests.
The program's interface is very simple, with the pull-down menus at the top of the window we can select the exercises that we want to complete, and once they are loaded (that obviously won't always be the same), we'll only have to answer correctly. The exercises can consist in listening to a note and relate it to its symbol, or knowing if what is written and what you are listening to is the same.
All in all, Solfege is a program that is very useful to learn sol-fa, and to revise our knowledge about the music world.