Pi Crust - Easily Connect Electronics to the Raspberry Pi - https://www.pi-supply.com/product/pi-crust-easily-connect-electronics-to-your-raspberry-pi/
This is a PCB that brings sanity to Raspberry Pi headers.
See http://picru.st for more.
- Really compact - sits inside the surface area of the Raspberry Pi and adds less than 2mm to the height. If you have a case for your Raspberry Pi, this board should fit inside it.
- Pins are grouped together: GPIO, I2C, SPI, UART and power.
- Every pin is clearly labelled.
- Connections: 2 x SPI, 2 x I2C, 1 x UART, 8 x GPIO
- Uses female headers instead of male headers - you can poke jumpers right in.
- Lots of GND and 5V pins - you need those guys a lot. These pins are duplicated where it makes sense (e.g. within the UART, I2C and SPI groups).
- All thru-hole components - you can solder it yourself.
- Cheapety cheapy cheap.
- Open source hardware.
- More photos here
See http://picru.st for more.