The AVS Sample App is great to play with on a Raspberry Pi as a cheaper, more home-made version of Alexa. However, both the wake word engines (TrulyHandsfree and Kitt.AI) have problematic licenses.
By free, I'm looking for an engine where both the code and the training data provided is licensed for use for both personal and commercial uses. The TrulyHandsfree engine has a very restrictive license permitting personal use only, and the binaries they provide stop working entirely after about 3 months to try and discourage unlicensed use. The Kitt.AI engine is slightly better, but their webpage specifically says that the "Hacker" pricing (their free tier) does not have a commercial license.
Does Amazon provide a more free wake word engine, or are there any engines that support the AVS sample with less restrictive licensing?