There are a lot of apps out there that pay lip service to security and privacy, but Signal was built from the ground up with the goal of letting people easily communicate without having to worry about being overheard. The Signal app is a complete phone and SMS client replacement (though it works just fine as a standalone app, too) for sending and receiving encrypted calls and messages. A recent update has greatly improved the app's look and feel, proving that security and usability don't have to be at odds.
For passing links, web addresses, or clipboard data between devices, Join is a great option. Setup and customization are easy and Join makes it simple to specify which notifications and actions you want to enable for each device. It even syncs SMS texts to a Chrome browser or the dedicated Windows 10 app. Unlike Pushbullet, it doesn't require a monthly subscription to use its features to the fullest. Our favorite features are its remote screenshot and screen-capture capabilities.
Privacy stalwarts rejoice! Tor now has an official (and modern-looking) Android app. The Tor project operates under the principle that "internet users should have private access to an uncensored web." Make sure to read the overview of how Tor works before you start using it, as it addresses specific types of privacy threats (and does so very well). The Tor browser may perform more slowly than other browsers, given its complicated inner workings, but that drawback should be negligible for the users who appreciate and rely on its protections. New Droid Apps
Your bag of holding for internet content, Pocket saves articles, images, and videos for later reading. We especially like how it reformats articles for more comfortable reading on a mobile device, and how it syncs content to your tablet, phone, and online account. With the close integration between Pocket and the Android sharing tools, you can pocket just about anything from your phone. Android App
Combined with Google Drive, this is an excellent choice for collaboration, especially given how feature-rich the mobile and web apps are. Once you create a document, you can add people to it, so that they can collaborate. Once they accept the invitation, you can create a multitude of documents — similar to what you can do with Microsoft Office — and have your team collaborate in real time.
Weather Underground combines a slick design with a focus on really useful weather information. We particularly like the ability to report weather conditions in your area and the extremely useful comparative forecasts that deftly show how conditions have changed since yesterday. With an accompanying set of useful widgets, it's the best weather app on Android. Droid App