If you use Android, you have a Google Account, and that means you have access to the excellent Google Drive cloud storage service. With Drive, you can easily access synced files across all your devices no matter where you are. With the additional Docs, Sheets, Slides, and Photos apps from Google, Drive is the center of a productivity hub on your Android.
If you're looking to learn another language, Duolingo gamifies language learning with bite-sized lessons and a friendly interface. Starting with simple vocabulary and building from there, Duolingo is your guide to learning a new language or brushing up on one you already know. The more you use the app, the more you unlock and—with practice—the more you learn. This free app currently supports Danish, Dutch, French, German, Irish, Italian, Portuguese, Spanish, and Swedish. Or more practical choices, like Esperanto and Klingon. 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.
The library is an often-overlooked public resource (and some are modernizing quickly), but OverDrive brings it back into the fold with the newly redesigned, Libby. Supported by over 30,000 libraries worldwide, the app lets you access your local library's array of available ebooks and audiobooks. Use it to download titles, place holds on titles not yet available, and consume your borrowed content. The only requirement is a library card (or its digital equivalent). Droid Apps
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.
This calorie counter and exercise tracker aims to help you lose weight the old-fashioned way—expending more calories than you take in. With its smart design and an extensive library of foods, it makes quickly logging the calories you take in and what you burn while exercising a snap. A barcode scanner makes it even easier to log that post-workout snack. This fitness app also plays nice with other such apps, so your data won't be tied up in just one place. MyFitnessPal won't give you a whole workout regimen, but it can make you more aware of your habits. PCMag has a full review of MyFitnessPal for the iPhone. Droid App