We have spotted a real unicorn: an established iOS app has come to Android with a smoothly functioning app that boasts Material Design from the get-go. It's neither a port of their Apple predecessor nor a half-baked effort just to claim cross-platform compatibility. If you're into a relatively minimal interface and an Inbox Zero type of approach to task management, Swipes is worth a look.
The workflow, if you want it to, can be a lot like Google's Inbox is for Gmail. Speaking of, the developers promise integration with Gmail soon for Android users. Also, Google Calendar is on the way, but with less clear of an arrival date. At this juncture, the sole third-party integration for the Android version of Swipes is Evernote, which is probably the most important one. Tag a note in Evernote with "swipes" and Swipes will add it to your queue when the due date comes up.
Usage can be pretty simple. Swipe right to mark a task as finished and left to save it for a later date. This can help you deal with the overwhelming nature of some other productivity schemes; it can be a little disheartening to see everything that you haven't finished, all the time.
Also, yes, you can switch between light and dark modes. I know there are a lot of people who will be very pleased about this. Otherwise, the interface is not very customizable at this juncture. I don't love that yellow, but it is common to Swipes on its other platforms as well. Note that when you move to the right, the interface is green as you look at completed tasks. To the left is red, where you can view snoozed reminders.
After a couple weeks in public beta, Swipes hit the Play Store today. You can download it yourself or stay on top of things by joining the beta community on Google+.