Nine is a very reliable email client designed to work with all of your accounts. The clean interface and the optional conversation view make reading and replying to email intuitive. One of the coolest features is the ability to customize the notification actions, including an incredibly useful "Mark as read" option. It isn't cheap, but it's only a one-time $14.99 charge for a much-improved email experience that also integrates calendar, contacts, notes, and tasks functionality.
Amazon is the internet's marketplace; the one place where you can buy just about anything—and it's cheap too! On Android, two of our favorite features are the integrated Alexa voice commands and the photo search, which makes it easy to surreptitiously compare Amazon's prices to those of the brick and mortar stores it is killing. Amazon Video-related functionality has been moved over to its own dedicated app, but all of its other consumer services, including Fresh and Restaurants, make an appearance. Prime members rejoice; there's never been a better way to stay connected with your Amazon lifestyle. Android App
File browsing is something everyone inevitably has (or wants) to do, so you might as well do it with a capable, fantastic file browser. Solid Explorer is pretty much as good as it gets in the file explorer apps realm. It features Material Design, archiving support, support for the most popular cloud services, and even some more power user stuff like FTP, SFPT, WebDav, and SMB/CIFS support. It looks great, it’s incredibly stable, and it just works well. There is a 14-day free trial with a $2.99 price tag at the end of it. This is, by far, the best file manager on Android for most people. Droid App