Witness

 

Witness Email, an app for macOSiOS and Android, is a customised RSS reader for an online email-based newsletter.

The app provides readers of the newsletter with easy access to previous issues. It also adds offline caching, so that issues are available to read without an internet connection (for example, whilst on the London Underground or during a flight), and push notifications, so that subscribers are immediately notified when a new issue is available.