TweetDeck - TweetDeck is your personal browser for staying in touch with what’s happening now.
Listmonk - Send e-mail campaigns from a powerful dashboard. High performance and features packed into one app.
Tweetbot - Sync your timeline across your iPhone, iPad, and Mac. Mute tweets by user, hashtag, tweet source, or keywords (including regex). 3rd Party support for image, video, read later, and timeline sync services.
Sendy - Sendy is a self hosted newsletter app that sends emails 100x cheaper via Amazon SES
TweetCaster - TweetCaster is a third-party Twitter mobile app that is available on Google Play and the Apple App Store.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.