How to secure input in php
Sanitizing data means Remove any illegal character from the data. In php you need to impliment this one for secure input for MySQL.
Getting checkbox values on submit in PHP
If you have multiple options, then you want to get the checked values to store them in variable on form submit, Then you can use this technique. A good method which is a favorite of mine and for many developers
Getting the screen density programmatically in android
Getting the screen density programmatically in android