Who they have experience in chatting app and they can prove to us by showing their app and have done similar project.
1- We need an app similar to wechat. (Got all the future that Current Wechat Have)
The points that are important for designing and developing of app for us
1- The structure of app should be powerful to handle million of users
2- There is need to add three simple functions in group chat
3- Making of ios, Android and windows version of app
4- Developing of webservice version of app
5- Designing of user interface is very important. it should be simple and user friendly(we will provide you with some UI examples)
6- Creating a chat group for event . ( Every people can Participate at the poll ) .
7- Share the group with people you want to join with a simple URL .
Price can discuss..