Having fun playing with sigrok pulseview and a Leonardo.
They are good for just looking at I2C and SPI to see how they actually function on the bus wires.
I recently got one of these;

DANIU DSO188 Pocket Digital Ultra-small Oscilloscope 1M Bandwidth 5M Sample Rate Handheld Oscilloscope Kit - Banggood
Simple little scope, just doing some hardware mods to it, power switch and signal input socket not the most practical.
Single channel, but great to just grab and hook to a data line to see if there is any action, or ripple on a power supply line.
Tom...
