Wattagio is powerful battery assistant. It informs you about current battery health and helps to decrease power usage. Flexible settings in the application give you options to customize your profile to meet your needs.
I love the app, it is what I wish Activity Monitor should have been and even more! I also love the name!
I can't fully appreciate it because I need to use it more for it to gather enough statistics about the apps I use.
But still, I already found at a glance that an app I thought inofensive was using much more energy than I thought.
Also, it's really reassuring seeing that my battery will last at least 4 more years ^_^
Sleek interface • Useful menu bar icon and menu • Even more useful stats