Rebuild .apk file of Android project on Eclipse without run

For Mac: Eclipse -> Preferences

For Windows: Windows -> Preferences

then, Preferences -> Android -> Build.

Uncheck "Skip packaging and dexing until export or launch. (Speeds up automatic builds on file save.)"

Lastly, restart Eclipse. You will realize that when you change something on your code and save it, .apk file of your project will be updated corresponding your changes on your code.