Hi,
This is Tauqeer Ahmad. I have created landing pages (single page sites) and multi pages sites from scratch in past and I am confident that I can be of help to you.
Tell me about your app in detail as who it is for, what it does, how it does it(optional) so that I can decide UX design. we can discuss UI design, if not I will offer you few options for you to select. I will require original images from your app so it has only relevant information and based on that I can create icons, graphics for the website. This is necessary so the site is made uniquely for the app.
You can connect with me, so we can proceed with understanding your requirements. I personally like to communicate regularly to ensure more than 95% match between requirements and product.
Best regards,
Tauqeer Ahmad