According to two posts on Dribbble, the design is based on a app store-like interface from an old unfinished project.
Tap bar UI of an old project. Animation was nifty; highlight indent warped in and out via a minimize and expand effect, on tap.
Sentry has published quite a few concepts lately including ones for iOS App Switching, Lock Screen Toggles, Quick-App-Switching, and Do Not Disturb.
Take a look below and let us know what you think in the comments.