Does there exist some kind of plugin or lightweight method of determining whether
A. A user is using a mobile device
B. The user has a particular app
C. The user does not have a particular app.
And depending on what criteria the user satisfies, display a prompt (modal, overlay, pop-up) that allows the user to view the app (if installed) or to install it (if they do not have it installed).
I realize "A" can be achieved by using media queries but I am not sure how to configure the others.
I've seen this done on many many sites so I know that it is not uncommon (view screenshot). Ideally I just want to implement some quick solution. I'm looking for something similar to "Hello Bar" for mobile only, I suppose.
Any help will be appreciated.
Example: http://i.imgur.com/VkWKu.png (the prompt at the top of the browser)
I ended up finding this:
Which is exactly what I was looking for and will work in tandem with the other solutions.