Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Normal
I may not be following this right, but wot Iv got in my head that you need is an adjustable timed solenoid, I use them for pneumatic systems at work, they have a adjustable time setting, plus a 'test' (overide) button that you can activate as and when you want.