Another great use case. Thanks for the contribution!
Do you normally read through people's comment before replying them? I doubt if you do because of you did you won't have replied with this type of post.
Everyone is skeptical if the apk.zip file that you intend to sell isn't going to steal the information of those that have unzipped it in their devices? Because for you to have thought of helping other steal the private keys of an innocent person I'm sure you might be capable of stealing those that are going to patronize you.
Op, why don't you take this idea of yours and channel it into something more useful rather than engaging in an unethical act. You'll be surprised of what you'll be able to build rather than for you to waste your talent on stealing private key/secret phrases.
Without giving a proper answer. 
Both great contributions for the thread. I appreciate all of you taking the time out of your day to bump my post giving users more ideas on how to use my software. Thanks for the feedback lucious, I gave it right back to you. Keep the contributions coming so I can keep my post at the top!!