The CHECK~IN app is designed to allow those who live by themselves to send daily CHECK~INs to loved ones notifying their safety. You can send either one or two CHECK~INs per day, and they must be four hours apart. You can send a CHECK~IN from 2 hours before to 2 hours after the scheduled time. There are two different types of users: senders and receivers. Senders send the CHECK~INs and Receivers receive them. If the sender hasnt sent their CHECK~IN, than the receiver will be notified at 5pm, 9pm, and 12am. They will also always be able to check on the app. Receivers will receive push notifications when the sender has sent their CHECK~INs, and senders will receive notifications during their CHECK~IN time, reminding them to CHECK~IN. Receivers can only receive from one sender, but senders can send to as many receivers as they wish.