So, thouse of you in the know.... Are there any apps for Android devices that you're aware of that are useful in aiding D&D game play? Particularly as a DM (combat tracking, note taking, etc.), but anything you think that makes gameplay and setup easier is good, too! 
While I'm specifically looking for apps to aid in traditional face-to-face play, it wouldn't hurt to include apps that help online play for those in our community that want them.
Please... Let's not turn this into a discussion of what WotC is or isn't doing to facilitate digital tools—that's been done before, and it doesn't go anywhere productive. Instead, let's focus on what we, the community, can offer—whether that's finding existing tools that help, or (if someone is so incline) producing new tools.
This is the dice roller I liked the most. It's simple and quick. The default features a 3d20 for The Dark Eye but can easily be adjusted. Other than that, I don't use anything on tablet but I've got a spreadsheet on the laptop that I use to track initiative, AC, HP and status effects.
https://play.google.com/store/apps/details?id=de.duenndns.gmdice