Put simply, Guice alleviates the need for factories and the use of new in your Java code. Think of Guice's @Inject as the new new. You will still need to write factories in some cases, but your code will not depend directly on them. Your code will be easier to change, unit test and reuse in other contexts.

Deprecated. RoboGuice 3 smoothes out some of the wrinkles in your Android development experience and makes things simple and fun. Do you always forget to check for null when you getIntent().getExtras()? RoboGuice 3 will help you. Think casting findViewById() to a TextView shouldn’t be necessary? RoboGuice 3 is on it. RoboGuice 3 takes the guesswork out of development. Inject your View, Resource, System Service, or any other object, and let RoboGuice 3 take care of the details. RoboGuice 3 slims down your application code. Less code means fewer opportunities for bugs. It also makes your code easier to follow -- no longer is your code littered with the mechanics of the Android platform, but now it can focus on the actual logic unique to your application.