Clear-cut products of push notification for iPhone?

I need some thoughts regarding clear-cut products of push messaging for iPhone.

Most of the software cost nothing to download and allows making free calls, text chatting, instant messaging and conferencing. This VoIP software is suitable for both mobile and fixed line applications. Along with making cell phone calls people are using broadband facility too. Push mail is a good application made available from most of the carrier's networks. It allows the e-mails to land with your mobile phone with prior best notification. With this application, not simply business personnel but everyone is able to check their important e-mails whenever, wherever they really want. This offers an even more convenient technique of managing e-mails.