Hey dseg, made a simple java app that can do what you want. (just need to have java8 installed (1.8 latest))
Basically choose http or https,
enter a URL you want to request (ie. www.google.com
enter the interval of the requests in minutes,
and click start.
Then you can click the x to minimize to system tray so it doesn't bother you.
It logs the successful requests so you can see its running.
I'll put the source code on github in a sec in case you are worried it is doing something suspicious
link to zipped jar file on google drive: