Many times you’re doing things in parallel. If you want to do your best you should really only concentrate on one thing at a time. There are, however, many tasks that can be done in parallel. Buying groceries and listening to an audiobook or a lecture. Doing 2 or 3 maintenance chores on your computer, switching between them when there’s a wait etc.
Have an online app that can track many tasks in parallel. You can start one task and a timer for it, then when you have to wait and switch to a new task you can start another timer for that as well. Both timers running in parallel until you stop them.
Have peace of mind. Know when my kids are not where they are supposed to be.
Have an app installed on their smartphone (whether you tell them or not is your decision) that can take your remote commands. When you know they are supposed to be with a friend for a certain amount of time you define the time frame, the location, and radius. If they go out of the radius within the time frame allotted, you’ll get an alert and can see where they are currently. Can also be used to signal you if they are supposed to leave and they are still there 🙂