You need to host the website on a web server so someone from the outside can access it. You can either install a server locally on your PC and configure your network to allow outside access (free but not really secure), or you can get a hosting account with someone who offers web hosting and...
Ok, so I took a look and I noticed that the app you referenced did not open the camera in a separate app and instead prompted a request from the browser for a request to access the camera. My guess is that they're using the canvas element to display the video, which since it's in the browser...
Look into the z-index CSS property: https://developer.mozilla.org/en-US/docs/Web/CSS/z-index
You might need to give the video a lower z-index and then the button a higher z-index, which will tell the browser to display the button over the video.
What does your code look like? You'll probably have to pass the date as a parameter in your URL when you do the page reload, then update your date picker code to look for that parameter and change the date to the value of the parameter if it is present.
Basically it's a web server you run on your computer instead of out on the internet. There's certain things that won't work if you just load up an .html file from your computer's local hard disk, so you can install a web server on your computer to fetch the files you create for you and serve...
Viewing that on my phone, the video capture window is my phone's default camera app, so it is outside of the browser entirely. There won't be any way to have a message over the capture window because it is outside of the browser.
Can you make a video of what you see in action? I suspect that the mobile video camera screen may be different from a standard HTML video and may be a part of the "browser chrome" so you wouldn't be able to overlay anything on top of it, just like you can't make a webpage element overlay the...
What does your full file with the form look like? It looks to me like you are missing the session_start() in the second example if these are separated out into separate files, but that could just be the way you have the code split up.
Are you starting the session before outputting the form...
If the next question depends on the...
Say you have your marquee in the following code:
In CSS you can have: