The best Reminder App for Android phone

I tried so many reminder app on Playstore, but non of them satisficed me which cannot run on the background and I always miss my schedule stuff.

I tried several reminders like:

1. https://play.google.com/store/apps/details?id=com.remindme
2. Reminder with Alarm🇺🇸 To Do List, Daily Reminder
3. Todo Reminder with Alarm
4. Just reminder with alarm

 - I though this one is the best at first, but after I switch off my mobile then it will work properly again.
The best one I used is this one: https://play.google.com/store/apps/details?id=alarm.clock.calendar.reminder

Although it came with the advertisement, just the google advertisement type. Don't bother it.

I am not 100% sure that this reminder app will not let you miss your schedule.
But so far I found this app is 99% perfect!

For some reason, it was NOT working properly recently.
I don't know why, may be others APP effected. 

I found another Reminder App, it working fine, but after I switch off my mobile one day, it not working properly. My mobile problem. May be.

The App I use is: BZ Reminder