原文出處： How much money do you make from your Android application? 這方面的答案僅供參考： Stanley Idesis (2016/ 4/ 10) app : Quotograph 沒有內嵌廣告，採取免費使用的策略，另外有IAP(in app purchase)的模式，不過發現在play store 用戶的付費意願非常低。
This Notes is according to the udacity free course : Android Development for Beginners Lesson 3A : Object Oriented Programming This is the most important class in this course Define a method
This Notes is according to the udacity free course : Android Development for Beginners Lesson 2A : Solving Math Problems So we know how to let our machine to display the number, and then we want to ask them to help us do some math work.
This Notes is according to the udacity free course : Android Development for Beginners Lesson 2A : Do Something When Button is Clicked We finish the layouts arrangement and we start to enter the most important step which is let your app can interact with users.
This Notes is according to the udacity free course : Android Development for Beginners Lesson 2A : Create a New Project Plan How to Build the Layout Build layout Follow the instruction below to build up a new app called "Just Java" use empty activity .