FeedbackSpark's answer:
Range of powerful features designed specifically for digital product teams:
madkudu - We’re building a better knowledge base
Back Market - the refurbished (super) market
Mobbo - Mobbo provides analytical insights to benchmark, compare and optimize mobile apps,
Survey Monkey - Create and publish online surveys in minutes, and view results graphically and in real time. SurveyMonkey provides free online questionnaire and survey software.
Alinean - Alinean offers dynamic sales and marketing tools, empowering B2B vendors to better connect with and sell to economic-focused buyers.
Google Forms - Simple web forms from Google.