once.to is a modern, all-new URL shortener striving to become the most versatile and feature-rich tool for the job in the whole world. Its highly optimized server code makes it easily beat similar services in terms of speed and throughput (proof: https://once.to/fast).
Among other, more commonplace, features once.to features a unique rule engine allowing the user to redirect their visitors based on their country, language, browser, operating system and so on, or even add randomness to any rule.
once.to also offers branded links and advanced link analytics/statistics, even on a free plan. There's also a month-long free trial available for trying out the premium functionality.