What does "nagware" mean?

Software that displays a message requesting that the user register it.

Nagware

Common synonyms include: aggressive monetization, coercive marketing, insistent, intrusive design, monetization prompts, nagging.

noun, slang

noun, slang ·Moderate ·College level

Noun

1
Software that displays a message requesting that the user register it. slang, uncountable

From nag + -ware.