There's a plethora of juicers out there, but here's one citrus press that uses some pretty simple scientific principles to squeeze every last drop of juice out of the fruit of your choice. Sometimes to move forward you have to simplify, and this lever operated juicer uses the simple scientific principle of levers.
Unlike many juicers, the RA Chand citrus press doesn't have any independently moving parts or motors. Yes, you have to use a little bit of elbow grease to move the lever down all the way, but the stainless steel construction will crush the fruit until there's not a literal drop of liquid left. The citrus press also eliminates most pulp since the press doesn't shatter the membranes of the fruit that cause pulp in the first place.