Is there any good tutorial for custom keyboard implementation in iOS?

I need to make a custom keyboard for a regional language "Tamil" and I had to bring in tamil font if the user presses the custom keyboard keys. Is that possible? If so any tutorial or resources available?

Thanks in advance.

Does IOS custom keyboard?

Custom keyboards are enabled in the Settings app, under General > Keyboards. Once enabled, the keyboard is available during text entry within any app, except when editing secure text fields and phone number fields. People can enable multiple custom keyboards, and switch between them at any time.

http://cocoacontrols.com/platforms/ios/controls/amkeyboardnumberpad , it is a simple key board but you can see how it is implemented for a quick start.

This site has really good open source controls for IOS. Hope it helps