Android offers a custom plugin for the Eclipse IDE, called Android Development Tools(ADT). This plugin provides a powerful, integrated environment in which to develop Android apps. It extends the capabilities of Eclipse to let you quickly set up new Android projects, build an app UI, debug your app, and export signed(or unsigned) app packages(APKs) for distribution.
Note: If you have been using Eclipse with ADT, be aware that Android Studio is now the official IDE for Android, so you should migrate to Android Studio to receive all the latest IDE updates. For help moving projects, see Migrating to Android Studio.