From LQWiki

The term guiltware can mean:

1. A piece of freeware decorated with a message telling one how long and hard the author worked on it and intimating that one is a no-good freeloader if one does not immediately send the poor suffering martyr gobs of money.
2. A piece of shareware that works.

This article is based, in whole or in part, on entry or entries in the Jargon File.