This stand allows you to house your post-it notes at a convenient 15° for easier viewing.  In addition, you can use it hold your pen, including larger pens like the Twsbi Eco Fountain pen (as pictured).

This stand is inspired by the model "Post-it memo and pen stand 15° tilt" by T.Uehara, which can be found here: https://www.printables.com/model/418990-post-it-memo-and-pen-stand-15deg-tilt