Simple Swim Timer Alert that can do quarter of a second intervals

The standard swim time alert can only do whole numbers.

For example, if I want to maintain a pace of 1:51s/100m over 1800m in a 25m pool, I would ideally like an alert every 27.75 seconds - so it goes off as I turn. But the standard app can only set a time alert at 27 or 28 seconds.

So it would be great to have a field that can be set to xx.25, xx.50, xx.75 or xx.00

Is this possible?