Screen time "timer" for laptop?

Hi, does anyone know of a simple tracker or timer to limit internet screen time on a laptop (Windows)? I'm looking for something that ideally starts when you open your browser or click to start it, provides a warning before the time is up, and then stops your browser usage when the time is up. If there are features that allow a time "bank" for unused time, or allow you to adjust the time easily (e.g., if child watched a 30 min TV show you can adjust to allow only 30 min of internet instead of the usual 60), all the better. And ideal too, if the child can enter the screen time they want to use now (e.g., gets 30 min and wants the timer to stop usage after 15 min, to save 15 min for later in the day).

We have a young child who watches YouTube videos and plays video games on the browser, on a Windows laptop that we provide access to. We currently use a visual timer, but it is a pain to remember to set it each time, or for kiddo to set it, and often kiddo wants to finish some little part of a show when the timer goes off and then doesn't notice that 30 minutes have passed, and we don't want to have to monitor so closely that we have to watch the clock. Kiddo would also like an internet timer that just pops up so you don't have to remember to set it, so luckily we all want the timer and it doesn't need to be something with security to keep kiddo from disabling it.

I've researched this online and found a ton of parental control software, but it is all way more than we need. We don't need filters to block websites or timers across multiple devices, or geofencing (we might need these things down the road but not now). Since my spouse doesn't use a smartphone, we'd prefer to have something we just download onto the laptop and not need to use a phone to control it, if possible. When I tried to find software that just tracked time, I found things for contractors who keep track of time for invoicing clients but nothing that met our needs. The timer that comes with Windows utilities is too subtle (you have to open it, set the time, and then it just goes off but there is no warning, you can't see it if you're using the browser, and you can't snooze it or get the internet to stop when it goes off). 

We might just have to purchase something like Net Nanny, but since we don't need anything that thorough at this point, I'd much rather get something simpler if possible, and ideally either cheaper or one-time fee to download, or even free if it exists. Any ideas? Thanks in advance!