Hi there!

I've been working on a similar module for a while. My module, thus far, has been limited to the Drupal php framework. However, the core of the functionality is naturally bound to the front-end.

Along the way, I've learned a lot from my users:

• use-cases: like if we can't go to the app, go the store instead, separate iPad/iPhone Apps
• edge-cases: Android Chrome needs Intent Urls instead, and doesn't like the iframe trick
• fancy-cases: sometimes it would be nice to pass the current query-string to the App URL
• testy-cases: So many changes, it would be nice to get some testing going to know we didn't break anything and get ✅ pretty green checkmarks

I realized since most of it is front-end I should move that to it's own npm/bower project, then I found you've already got a name and a start.

I'd love to collaborate! 😸 Let me know what you think about what I've got.

Core Front-end
https://github.com/robcolburn/drupal-app_link/blob/7.x-1.x/js/app_link.js

Test Script
https://github.com/robcolburn/drupal-app_link/blob/7.x-1.x/test/app_link.js

Note: Code was developed as a Drupal module, so code style attempts to follow Drupal's guidelines. I personally, don't have any preference on naming or code-style, and I'll readily adapt to yours. Though I would like to bring over niceties, like linting, testing, and automation.