Is there any way to create a reminder that pops up a screen alert. Web based for mobile ?
Of course! ANYTHING is possible!
Well, first you need to keep a database of some sort that would know if the alert was shown or not.
If you want to show an alert, just add it to the webpage. Many ways to do that, but, you need to decide the best way to display it. Is it for every user? Is it per user? Do you need to know if a user has viewed it?
You could just have one page with the alert on it and move to that page. Then, if the user clicks on it, move to the live page. Or, you can use an actual pop-up that is controlled by Javascript to load once the page is displayed. Lots of ways to handle this.
I am after a web based script database driven where a user logs in sets a reminder by date time and message and when its executed pops up an alert or window. Been told if browser not open can only send reminder by email.
Yes, you are correct. You can NOT force a webpage to open on a computer. You can send PUSH notifications. They pop-up in the Windows 10 notification area. You can Google " php push " and find tons of examples. Here is one to start you off with: PHP PUSH