Java Android Source Code

1- A am starting to android apps. 2 -I want programmer to write source code in java for android phone, and use eclipse to convert to apk file. 3- I will then be able to use and adjust this java to change ( ie pictures, web site address, etc) 4- This will allow me to see the code in operation and how I can adjust or modify it. 5- Want code to access phone funtions so i know how to get these function from within an app (such as dialling number, engaged function, answer function,etc. 6- I want to use theses functions so i can manipulate the uses of a phone.