Blinkist sends daily notifications at the time that fits you to promote their "daily pick", which is their daily free content, selected by their curators. A classic trick to make sure users come back on the app as often as possible and drive retention.

Karma sends daily notifications around its core value proposition: using the app makes you an environment committed person. Of course, this type of notification is sent around specific hours when you may be thinking about your lunch or your dinner.

Reflectly sends an inspiring quote everyday. Users get free content and can share it easily on social media. High impact for low effort on Reflectly's side.