useful

Having a beneficial use; serviceable.

Being of practical use.

Being of use, advantage, or profit; valuable for use; suited or adapted to a purpose; producing or having power to produce good; beneficial; profitable; serviceable.

Useful invention.

Full of use, advantage, or profit; producing, or having power to produce, good; serviceable for any end or object; helpful toward advancing any purpose; beneficial; profitable; advantageous.