A Greases Gun pressures release button
Build a grease gun that you can press a button to release pressure between the nipple and the gun so the gun will release easy.
The easiest way to get places - teleportation. A device you hold easily in one hand and allows you to choose any destination to teleport to. With the press of a button you're then instantly teleported to your chosen location.
A tool cabinet that tells you when tools are missing.
A tool cabinet could be produced that has sensitive scales that knows the weight of the tools in the cabinet, each tool could be weighed in or checked in or the Tool Cabinet could be supplied new with Tools in it, so the Electronic interface or a Bluetooth App on your phone can tell you what tools are missing or most likely what tools are missing. The cabinet could have a light on it that turns Red when tools are missing or being used and not in the cabinet. The Cabinet could have a green light...
The ability to be able to plug in, one or more, rechargeable power tool battery, to a device attached to a wheelbarrow wheel, to make moving heavy loads/ concrete etc easy.
Better safety for road traffic controllers
Hand held traffic control signs need to have flashing LEDs around their outer edge.