Turn off iMessage
Once you're done with moving your data over from your iPhone, you must turn off iMessage manually. Quite a number of users reported that they were not able to receive their mesages after switching to Android from their iPhone, which is why Apple made a “Deregister iMessage” tool to let users deactive their iMessage. You can deregister iMessage at this link.
There’s an app for that
If your handset is a new device from Samsung, Sony or HTC, then you'll have the benefit of a dedicated app to help ease the moving pain. Samsung uses Samsung Smart Switch that lets you transfer all your contacts, photos, messages and more from your old Android, iOS and even BlackBerry devices. Check out Samsung for more information.
As for Sony Xperia users, the Japanese company has its very own Xperia Transfer app that lets you move from your old iOS device to your new Xperia smartphone. Just download the app from the Google Play Store, and follow the instructions.
HTC uses HTC Sync Manager to help you move things from iPhone (contacts, messages, wallpaper, photos and more) to your HTC Phone. You can download HTC Sync Manager to your computer, then use the software to move your data over. Check out HTC for the full instructions.