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

To build the kit, you will need:

1. Soldering iron and basic soldering skills.
2. Glue or double-sided tape.
3. Basic tools (torx t5 screwdriver, needle-nosed pliers).

In addition, you will also need:

• 1 AAA battery
  an iOS or Android phone or tablet
  and compatible software.

Compatible apps are available via the iTunes and Google Play stores.

This kit is available immediately, and ships in 1-2 days.

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