This is a great idea and executed very well, however it looks like you are using the marketing resources from Apple for the iPhone graphic and the Available in the App Store graphic. You should be aware that the use of these graphics requires compliance with the App Marketing and Identity Guidelines for Developers: https://developer.apple.com/appstore/AppStoreMarketingGuidel...

Relevant Sections: For the App Store badge: "The App Store badge can be placed on a black or white background, on a solid color background, or on a background image, as long as legibility is not diminished. Do not place the badge on a visually cluttered or patterned background. If the badge is placed on a photograph or other image, it must be positioned in an area that is uncluttered and provides strong contrast and clear legibility."

For the iPhone graphic: "The Apple-provided product image can be displayed only on a white background. Never place the image on a black background or on any color or pattern."

I know these guidelines may seem ridiculous, and I often wonder what consequences may come from not complying with them, however given this is the core of your app, I think it deserves special consideration from you.