App that lets you input your own wake windows? (Huckleberry rounds out to every 15 mins)

Anyone have an app they use where you can choose your own wake windows, it sends you reminders, you can track the sleeps etc. I don’t necessarily want predictions of sleep patterns. I don’t like huckleberry for it as it makes you round it out to 15 min segments, I want to be able to input it to the minute.