Do you really know what a chat app involves ?
An indie developper is paid from $ 300 to $ 600 per day. It means you think this job will take only 2/3 days ?
When you want to hire people, you should describe better your project.
Why you want this app ?
What is your idea ?
What will be the functionalities ?
Prove your worked on the conception, and now you need someone to build the app. Don't throw a post like that without any info but "contact me".