In our opinion, the only thing the Raspberry Pi Shield Pi 3 and Pi2 is truly lacking is an I²C port. (Of course you may have guessed by looking at our product offerings that we are admittedly a little biased. No worries.)
The Raspberry Pi Shield TOUTPI2 is a non-invasive I²C adapter complete with level shifter providing you with a 5V I²C port for use with any of our I²C devices.
The I²C port points outward toward the outside edge of the board, and terminates directly above the HDMI port. The Raspberry Pi Shield TOUTPI2 does not consume the 40-pin expansion port, as it is equipped with a pass-through connector, freeing the 40-pin connector for other purposes, making it a truly non-invasive design.
This adapter provides a general-purpose I²C port, compatible with our complete line of I2C devices. Control relays, monitor current, and read just about any kind of sensor you can imagine.