Hello, Can you please provide more details what will be downloaded and what kind of messaging you want, And do you have any design for this app. Please provide more details about the work,so I can estimate exact cost and time. Please provide the sample/reference app. Can we have more discussion. I have 4 years of experience in php,mysql,codeigniter,wordpress,laravel,API integration,Android,Iphone,web services,social media integration,payment gateway,PSD to HTML.