The best alternatives to Tandemz are User Interviews, PingPong, and Formberry. If these 3 options don't work for you, we've listed a few more alternatives below.
What do you think of Tandemz?
AssemblyAI— Speech-to-Text API with superhuman accuracy
Recruit users from our audience of over 200,000 vetted consumers and professionals, or bring your own audience and build a participant database for any type of UX research.