Safely warms breast milk (and formula) to preserve nutrients and defrosts frozen breast milk. “Steady mode” warms liquids little more slowly with a water bath to prevent over-heating but still only takes 4:20 mins to warm a 90ml glass bottle of breast milk. “Quick Warm” mode heats it more quickly with steam. There’s an app you can download to your phone but I never used the app. It’s not required to use the warmer. The warmer beeps and turns itself off when heating is done so you know when it’s ready and doesn’t continue to heat the milk hotter than you want it to be. You can check out Youtube for review videos. I purchased it for just over $100 and used for 1 child. I was very happy with it because of the auto shut off means the milk won’t continue to heat once it’s to desired temperature and because the beep feature ensures I didn’t have to stand in front of it waiting while my baby was fussing for milk.