As per title, does anyone know of any software that can do this ?

I know there's a tacx app for apple devices that can do it but I don't want to buy an apple device.

Zwift can of course do it but it only does it in accordance with the virtual terrain, whereas I just want to set a high inertia and ride with that constantly.

Ideally the app would give set the inertia, give 3s power on screen, maybe interval power too, record the ride, and throw out a fit file at the end of it. I'm not bothered about seeing videos or riding or racing with others.

If not I guess I'll have to write my own, but thats silly if one exists :)

thanks
Paul