Pedal PI

Many FX pedal guitars with good quality are sold in music stores in general, but you can actually make your own in DIY, for example, Electrosmash which assembles Pedals from existing Open Source & Open Hardware.

Electrosmash Pedal-Pi is truly Open Source & Open Hardware, for experimenting with sound and learning digital audio, it is perfect.
Easily and read the guide, can encode the effects yourself by entering the ready-made effects from the forum, such as Clean, Distortion, Reverb, Looper etc.

Cool products, actually all are easy, sometimes brands that make expensive, quality may not be much different from commercial products on the market. nice!