The easiest way to apply solder paste onto a PCB is by using a stencil. But when prototyping, the layout of the PCB changes over time. For small PCBs often the stencil is more expensive than the PCB itself. So, using stencils for every iteration of the board is not very cost effective.That is where solder paste dispensers come in.
Hummel1717/Solder-Paste-Dispenser
Automated device to apply solder paste on to a PCB without using a stencil.
C++GPL-3.0