i think it depends on the terms&conditions of google's playstore. just because you are german doesnt meant you cant ge sued by american laws, and i know that german and american laws are quite dirrefent when it comes to compensation (schadensersatz).

suggestions: delete references to "Yo" from your product-name (name it Jo instead); "Yo" is a registered trademark; you wouldnt name a chocolate you created "ritter sport", even if your name was armin ritter