You want to start a healthy life? Take care of how much water you drink every day?
Water for Apple Watch is the best start.

Medical research says you have to drink 2L (8 glasses) water a day to become a more healthy person.

Water for Apple Watch aka Watermeter keeps track of your daily water intake.
Simply 1 tap on your wrist and a glass of water (250ml) will be added to you daily record.

You can simply force touch to reset the tracker for today.
Everyday the tracker reset it self so you can start all over.