Android上简单实现四大组件的插件化，供学习使用

一个管理所有Activity的库，可以任意处关闭任意Activity

A health management app which keeps tracks of your daily diet where a user can add meals which he consumes daily in accordance to the calories that he wishes to burn. Nutrical comes with a workout manager where a user can burn the excess fat and keep track of his health. It also comes with all the features of an activity tracker.

Singleton for managing CoreMotion ActivityManager and Pedometr