The article highlights several popular newsletters for Android and iOS developers, covering topics such as tutorials, news, trends, and tools. These newsletters are curated by experienced developers and provide valuable resources for learning and staying up-to-date with the latest developments in the field. Some of these newsletters include Android Weekly, App News, and Instabug's newsletter, which focus on providing a daily look at the latest Android news, as well as iOS development resources and tips. Other notable mentions include Objective-C Weekly, Swift Weekly, and the iOS Development Digest, which cater to iOS developers with tutorials, design resources, and technical topics. The newsletters are available weekly or daily, depending on their frequency, and offer a range of content that can help developers improve their skills and stay ahead in the industry.