Visuino - Visuino is a visual programming environment that lets you write programs from Arduino circuit boards.
My Devices - Drag and drop IoT project builder for Raspberry Pi
ArduBlock - ArduBlock is a graphical programming language plugin specifically made for Arduino circuits and controllers.
ioBroker - flexible and modular application for the IoT and Smarthome
MINIBLOQ - miniBloq is an open source graphical programming environment for Multiplo™, Arduino™, physical computing devices and robots.
Nim Home Assistant (NimHA) - Nim Home Assistant is an open-source home automation platform running on Nim.