Seattle-based BigDoor, the developer of online "gamification" software, which allows websites to add badges, awards, and other social gaming features, has acquired OneTrueFan, a San Francisco developer of social media widgets. Financial terms of the acquisition were not disclosed. OneTrueFan develops a community and web check-in rewards system. BigDoor said the buy will accelerate its product development and growth. OneTrueFan's founders were behind IGN.com, MyBlogLog, and Gnip.