There is a multitude of such products: Timpson are one such company
who have developed and marketed their own brand of "Scuff Cover".
Scuff cover products are sometimes referred to as a "Shoe Restorer".
Scuff cover products usually comes in either a metal can or a plastic
bottle. You will need to pick the correct colour of scuff cover
to match your leather shoes/boots: such as black, brown or navy.
The ingredients of a scuff cover product vary from product to product:
Timpson, for example, use a water based pigmented liquid. Scuff
cover products usually include a sponge applicator: you will shake
the can/bottle, then press the sponge - located at the head of the
can/bottle - against the scuff you are trying to cover.