On Thursday, Sauce Labs announced $15M in Series D funding from existing investor Toba Capital, the investor that led its Series C funding round of $5M. The additional funding will be used to enhance the company’s platform for mobile testing as well as continue to support its web-based application testing and support for the open source project Appium. The funding will also help drive an expansion of the company’s development team, infrastructure and international presence. Sauce Labs delivers a cloud-based testing platform that allows customers to automate parallel testing of web and mobile applications across different browsers, operating systems and environments. By automating the testing process and helping customers interpret testing results, Sauce Labs shortens the time to market for applications and dramatically increases application quality as measured by their ability to perform across a variety of end user environments. Thursday’s funding raise follows upon a year in which the company experienced 2014 revenue growth of 145% driven by significantly increased penetration into the enterprise market. Current enterprise customers include Salesforce, Twitter, Workday and Liberty Mutual. With an additional $15M in the bank, customers should expect the introduction of even more richness and sophistication to the Sauce Labs mobile and web application testing platform, and particularly the mobile platform as it responds to the dramatic proliferation of mobile apps across a variety of devices and operating systems.