Earlier quoted context omitted.
" Of course the way the world works today; instead of taking me up on the help they would probably just contact the police." Ok so try it this way. Contact the company [1] [2] and tell them you believe there might be security holes in their app (and make reference to cases like starbucks while pointing out that even if they are ok on that there could be other issues) and offer to tell them the results of your testing…
This sounds almost like extortion. I would not suggest doing this with security.
And it's done quite frequently by home security companies whenever there is a burglary in a particular area. "You're neighbor just had a burlary and you might be vulnerable as well!"
And the wording can be altered to suit one's taste or level of comfort.
Of course you can blaze a large "this is a solicitation across it" but I would suggest that if you aren't willing to push the envelope with marketing you are going to not make out as well. This is based on my many years of experience doing similar things. Business involves taking and assessing risks and rewards. (Everyone's level of comfort or ability to do this differs of course).
And it's not the same (nor was I suggesting) that you say to someone "hey I found a hole in your app and if you don't pay me I will publish the results of the security hole". Details matter.
By the way saying to a homeowner "I saw you have a few windows at your house that appear to be broken (that would allow entry!) and I'll tell you the broken windows if you pay me $50" is not extortion. Anymore than saying "You have an outdated HVAC and for $100 I will give you a proposal on the best system to replace it with".