The best alternatives to Okkiy are Snips, Hound, and WonderVoice Assistant. If these 3 options don't work for you, we've listed a few more alternatives below.
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AssemblyAI— Speech-to-Text API with superhuman accuracy
Mycroft Mark II is an open voice assistant allowing for more 3rd party integrations, and complete control over your data being stored and sold to advertisers.
Check out: Alexa Skill This is the new voice version of the beloved Mimi, the Hipster Cat Bot. She runs on Alexa as Skill and as Action on Google Assistant (on every Android 6+ phone!), both in English. Her invocation name is: "hipster cat". Try for instance "Alexa, ask hipster cat for a burger restaurant in San Francisco" and get inspired by new fabulous restaurants!
**2021 Update** Hootsy helps companies get more customers with live video. We no longer create voice interactive characters as shown in this post. We get people coming from here asking about it, so we wanted to clarify.