To delete a reminder, you can say “Alexa, delete a reminder”, and you will be prompted for which reminder to delete. On an Echo Show, the reminder will display on the screen with numbers, or on the regular Echo, the reminders you have will be listed.
Hopefully that saves you some time and aggravation of dealing with the Alexa app!
-Daniel
To the voicebrew.com Admin, exact same in this article: Link Text
To the voicebrew.com Admin, very same here: Link Text