One of those simple inexpensive tools that very easily becomes indispensible, the Narex Uniscraper is a narrow strip of spring steel, rounded on one end, square on the other.
A tiny burr on one face can be used to take light shavings or clean up finishes, with a round end for tight spaces and curves, the inside of a spoon bowl for example, and a square one for internal corners. The opposite face, without a burr, can be used for applying things like putty, or epoxy, or stropping paste. The corners are useful for poking crud out of gaps, or slitting box tape; you can shim things with it, stir things with it, set spark plug gaps with it, splint broken fingers with it... the list goes on.
200mm long x 14mm wide x 0.7mm thick