First of all I’m very sorry that MindBell does not ring as you expect.
Here is a checklist that I hope might help to get it going:
Does it ring when you touch the bell?
Follow every message that might give a hint.
Is the volume in the settings too low?
Try to change the bell volume in the actions section of the settings.
Have you activated the bell by the switch?
See intro how to activate it.
Have you specified the starting and ending times?
It will only ring after starting time and before ending time.
Have you specified the days of the week to be active?
It will only ring on the chosen weekdays.
Have you specified which actions should be taken when ringing?
Ensure the action you are missing is enabled: bell display, sound or vibration.
Have you been in a call when the bell tried to ring? Or did you mute the phone before or entered flight mode?
If so the bell won’t play a sound, vibrate or even display in that moment (depending on the corresponding option). That takes a new interval to try it again. With long intervals this might result in never hearing the bell ring.
Is there a chance that you simply overheard the bell? While in flow or very busy?
Choose another ringtone or enable vibration and/or enable notifications when the bell rings (needs version >= 3.1.0). Not forever, just to check.
Is ‘Pause audio on sound’ enabled in the settings?
Please disable that option. It doesn’t work properly on devices of some vendors, e.g. Samsung or LG.
Are you using any sort of power saver app or power saver mechanism?
Please exclude MindBell from any power saver app or power saver mechanism. This might be specific to you version, model and vendor of your phone or you might have installed some specials apps for this.
Please exclude MindBell from optimizing battery use following this description. The Battery button in MindBell’s help dialog should take you there.
Have you tried to uninstall MindBell and re-install it freshly?
Clear data first (it might make a difference).
On Marshmallow and higher please disable automatic restoring of app data after reinstallation.
Then uninstall and reinstall MindBell.
Have you re-booted your mobile to see whether that helps?
Please try that one, too.
You’ve found a solution that’s not listed here?
Please send me an e-mail. I’d be happy to add it to this list.
All this does not help?
Please use the e-mail button of the help dialog to send me an e-mail.
Do not forget to add your question or describe your problem, otherwise the e-mail will be ignored.