I would like to develop a messenger application similar to WhatsApp. The app will be proprietary, cross-platformed that should work with iOS, Android, WindowsPhone, and Blackberry,....etc. So, the messenger application should be working perfectly on smartphones. In addition to text messaging, users can send to each other images, audios and videos for sharing with their fellow contacts who are using the same application. So, in one work, the app should be similar to WhatsApp messenger and work perfectly with no bugs and anything else.
Please let me know if you need more details, and please don't bid if you didn't have previous similar work.