Dear Client
I've been looking through the Job Feed and found your work description extremely interesting.
Your job has a good potential and can be really successful.
I think I have a skills set that fits your the project. I've been working Web Site development, creating them from scratch, used to implement the responsive designs.
I'm very strongest at the front-end staff (HTML/CSS/JS, AngularJS, React.js), the back-end works (PHP, Python), Tools & IDE(Unit test, Jenkins, Git, Jira) and DevOps (Google cloud hosting, AWS, Digital Ocean, CloudFlare, VPS, Godaddy, Pleask and CPanel).
I will be glad if you can share the detail specs for the app and will be able to discuss it with you.
It's great you have a completed designs, backend APIs and specs. It's a very rare thing for customers and is your weighty advantage.