What's the word/phrase to indicate that applicability of something has been changed. For example in a given scenario, how to announce " enjoy tool "A" in its new application" in the form of "---- of tool "A"".
If you change applicability of something, it usually improves or upgrades the applicability.
You could consider using "upgraded version". To upgrade means:
Raise (something) to a higher standard, in particular improve (equipment or machinery) by adding or replacing components
[Oxford Online Dictionary]
I upcycled a stained tablecloth into curtains.
It basically means to reuse (discarded objects or material) in such a way as to create a product of higher quality or value than the original.
Also see: Upcycling vs Recycling.There's a subtle difference.
These words may be found useful, although not perfectly - repurposing, re-engineering, redoing, remodeling, renovating, revising, re-implementing.
Off label use is a widely understood humorous euphemism.
There are some others used by tradesmen that have escaped the narrow confines of their trade.
"Birmingham screwdriver" for a hammer, and by extension, any abusive tool misuse borne of necessity or laziness.
When you hold on to a found object, utensil, or part be cause it just happens to perform some odd job perfectly, it becomes "special tool #39" (or some other number). There is a folk etymology suggesting this came from an automotive tool kit that came with an empty slot.