Tools
Logic Analyzer
Saleae (and clones)
Helpful to analyze/debug data streams or measure ppm signal length.
saleae (works with linux)
The original costs about 120€, china clones begin at 10€.
The Seleae software for windows only allows their original hardware by setting the VID (Vendor ID) and PID (Product ID) in the saleae.inf file. This file is required as driver for the harware.
There is also an open source support for a lot of different logic analyzers (china clones) sigrok
DSLogic
Complete Open Software / Hardware Logic analyzer.
Currently the have a kickstarter campaign running.
iMax B6 charger (and clones)
There are various variants of this charger available (dual/quad output, 12 or 230V input, 200W version ...).
And also some clones, be aware, most clones are not calibrated -> poor balanced cells and overloading can happen !
An open source replacement firmware is available github.com/stawel/cheali-charger.
This allows calibration unlike the stock firmware.