诺加特通知甚至在卸载“关闭”后，即使在卸载“通知”之后，如何重置？ -- notifications 领域 和 7.1-nougat 领域 android 相关 的问题

I was a happy user of Notifications Off on Android 6.0.
It is an app that lets you block/unblock notifications per app.
On Android 7.1.2 blocking works but unblocking does not work, according to my experience and Play Store reviews.

My question: How to reset notifications, so that all appear?

I tried uninstalling the app, that does not unblock blocked notifications.
Anything easier than reinstalling the OS?

If I knew how Notifications Off works under the hood, I could maybe try to unblock manually?

I contacted the author and here is his reply:

Looks like a compatibility issue with Android 7. As a workaround to enable notifications you need to go to Gmail in the applications list and enable notifications there.

And indeed it is as simple as this:

1. Go to Android Settings.
2. Tap "Notifications".
3. Select "Blocked".
4. For each app that you want to unblock, tap it and move the slider to the right, for instance the 5th position out of 7.

The notifications are now reset to visible level again.