there are a number of options.
Is it a screwdriver with a transistor driven LED lamp and a battery, or a screwdriver with no battery, and a neon lamp?
The former measures resistance, and is good, as you say for checking bulbs and fuses. Used to be common for automotive wiring diagnostics, not often seen now. Useless for screws as the cheap steep tip chews off.
The latter is good for detecting induced voltages in dead cables that pass near live ones, proper voltages in live cables, and impending electrical storms. Useless for tight screws as the cheap steel tip chews off, and at high torque the handle shatters, piercing the flesh with shards of plastic and glass.
Or perhaps, just possibly does it look like the Doctor Who kind, with an eerie blue glow and a buzzing sound when operational, in which case it will open tins of paint, break locks, reverse transmat beams, halt alien battleships and cause Billy Piper to go 'ooh' at a moment chosen for optimium dramatic effect. Still useless for screws as the alien metal alloy shears the heads off in seconds.
If this let me know wher you got it - I'd like to try and make Billy Piper go 'ooh' myself.