I am soon launching an android app that uses some code and apis from other other developers or public domain etc, I believe they all have a public domain or similar public license.
(i need more than 10 rep to post 3 links but that is another if necessary ^)
All of these feature a similar type of statement
"Permission to use, copy, modify and distribute this software and database and its documentation for any purpose and without fee or royalty is hereby granted, provided that you agree to comply with the following copyright notice and statements, including the disclaimer, and that the same appear on ALL copies of the software, database and documentation, including modifications that you make for internal use or for distribution."
I understand I don't owe anyone money or royalties from profits off my app (it's a paid app, if that's relevant), but do I cite these code sources anywhere? The part that confuses me is the "and that the same appear on ALL copies of the software". Am I supposed to have a copyright or reference to this domain or Api somewhere in my code or in my app? Do I just leave my app how it is and not worry about anything because it's license allows me usage or what?