Given the task definition and input, reply with output. Given a travel related situation, and given a specific question about the situation, summarize the question into a title

There are several services that many passengers are not aware of on-board airplanes simply because they are unadvertised.

For example:

Coat compartments. You can hang your suit in the airplanes cupboard! just ask a flight attendant!
Birthday / wedding cakes. You can ask the reservation agent for wedding or birthday cake and they will bring it to you on-board!
Stain remover. In case something spilled on your shirt, you can ask flight attendants to help and they will bring you the stain remover wet tissue and it really helps!

Are there any other common unadvertised services that exist on airplanes?
Are there any common, secret services offered by airlines to passengers onboard?