Often hear it in conversations with young Japanese people. Is it their version of "like" along the lines of なんか?
Since you "often hear it", it's probably not the sentence-ending particle but filler さ, aka 間投助詞 (interjectional particle) in Japanese terminology.
In that case, anyway, it's a verbal filler to keep conversation that doesn't have any meanings or nuances unlike なんか, まぁ or "like". This filler さ always follows some words, never precedes or stands alone, as you pointed out as "ending" (thus, a particle).
さ can fall into 3 categories, that is, filler, interjection and sentence ending particle.
The interjection usage can function as prompting someone to do something or telling that you know nothing about what the opponent has asked. (The latter usage is spoken exclusively as prolonged さぁ.)
When it's attached to a terminal form of a verb or an i-adjective, or replaced with copula (だ or です), it's a sentence ending particle that adds a light-hearted feel. It's kind of dated in current New Tokyo dialect. You may still find it in writings, though.