This interesting kit uses a mix of Tindie + Shapeways to sell a product that has a 3D printed case. From Tindie:
PressurePen is a pressure sensitive stylus for iPad and Android tablets.
Unlike a typical stylus, it communicates how hard the user is pressing on the screen with the tablet via a standard audio jack. With software support, a light press can render as a fine line, while a stronger press will become a wide stroke. PressurePen is an open source hardware project funded, in part, by Kickstarter backers.
The PressurePen pressure sensitive stylus connects to any iOS (including iPad, iPhone) or Android (including Google Nexus and Kindle Fire) device via a standard audio cable (included). It is powered by one AAA battery (not included).
This package contains the kit of parts necessary to build one PressurePen pressure sensitive stylus, one MicroStylus tip, and a cable to connect to your tablet of choice. It does not contain the plastic shell. One may be ordered separately from Shapeways.com or printed on a 3D printer. 3D files are available at Thingiverse
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.