On that note, I also realized the connotation of "Tinder": combustible material which ignites upon coming into contact with sparks. Sparks fly when people meet - that sort of thing. Very clever indeed.

Also in Tinder gives you "matches" and the logo is a flame.

Can't start a fire without a spark

I thought it had to do with matches

I was ROLFing reading this

Starting a fire is the default meaning of the word.

Kindling as a noun is the twigs, leaves, moss or whatever used to start the fire.

Which is somewhat hilarious when you realize Amazon is telling you to burn books.

Doesn't sound bad when you take it figuratively. The fires that some texts kindled centuries ago are still burning.