A beta tester is also somebody who likes to have the latest version of ay kind of software (or hardware for that matter). You sign up with the manufacturer and get to use it before most others.
In the good old days to be a beta tester used to mean that you got paid for your effort, or at least got to use the product for free. When I say "paid" I don't necessarily mean in hard cash. Most of the time it meant that you got a full product for free once it shipped.
Nowadays this doesn't happen for different reasons.