I want to use twitter with my app. is there any demo app available for iPhone+MGTwitterEngine?
You can implement twitter API with two ways, such as OAuth and XAuth.
If you use XAuth means it is so easy to implement twitter api in your application. For do that follow steps,
1 Download the source code from this link,
2 Before, you must register to your application with twitter via your twitter account. After you can get API key, Consumer Key and Consumer Secret Key and also access token key and access token secret.
3 You have to send mail to api@twitter.com with API, consumer, consumer secret and application details, then they will replay to you.
4 After that you want to replace your keys in sample code and you can run.
Note: For OAuth, follow this link its very easy to use.
I hope it will help you.