I'm developing an Android app that keeps track of a users habits and sends scheduled reminders to the user even when the app has been removed from the recent app list. This is the problem I've been struggling with. I've tried using NotificationManager and AlarmManager alongside each other with a BroadcastReceiver, but I was unable to get any notifications when the app was closed. Now, I'm attempting to use Firebase Cloud Messaging which can send "messages" to the user even with the app closed, but I can't find any resources to create per-user scheduled "messages" directly from the app to my Firebase. I feel like I'm running in circles and I can't figure out how to have the user create their own scheduled notifications that work when the app hasn't been opened at all. Any suggestions?