XKCD comic #1190, entitled "Time", is a (still ongoing) series of pictures updating every 30 minutes This app lets you enable notifications that remind you every half hour to view the new frame of "Time" (or "Newpix", as some have come to call it). Within the app, you can view the current frame and get links to xkcd.com, the XKCD forum discussion of the strip, and an interactive GIF of all the frames together.