Mercury Editor: The Rails WYSIWYG editor that allows embedding full page editing capabilities directly inline.
Teaspoon: Javascript test runner for Rails. Use Selenium, BrowserStack, or PhantomJS.
Navigasmic: Semantic navigation for Rails using simple view level or configuration definitions.
Apitome: /iˈpitəmē/ An API documentation presentation layer for RSpec API Documentation output.
Bitbot: Rack based Slack bot with a responder DSL and support for Wit.ai natural language processing.
Schemattr: Simple schema-less column definitions for ActiveRecord that can change easily over time.