Intellectual property law is very convoluted when it comes to software. It is important to note the type of license associated with your software, as many publicly available SDKs and programs use the MIT license (in which monetization is legal), but many others also use the CCBY-4 license, which contains more restrictions on attribution, sales, and distribution.
It is also important to note the policy of the marketplace in which you intend on publishing your work. The App Store Developer Guidelines identify the following important considerations:
4.1 Copycats: Come up with your own ideas. We know you have them, so make yours come to life. Don’t simply copy the latest popular app on the App Store, or make some minor changes to another app’s name or UI and pass it off as your own. In addition to risking an intellectual property infringement claim, it makes the App Store harder to navigate and just isn’t fair to your fellow developers.
4.2 Minimum Functionality: Your app should include features, content, and UI that elevate it beyond a repackaged website. If your app is not particularly useful, unique, or “app-like,” it doesn’t belong on the App Store. If your App doesn’t provide some sort of lasting entertainment value or adequate utility, it may not be accepted.
4.2.6 Apps created from a commercialized template or app generation service will be rejected unless they are submitted directly by the provider of the app’s content.
For the bounty:
Can someone please explain, how WhatsAPI could be taken down (see github.com/venomous0x/WhatsAPI )? Is it illegal? What is the allegation?
The WhatsAPI closing statement references the Computer Fraud and Abuse Act (CFAA), components of which are codified in 18 USC 1030. Some potentially unlawful elements (in my opinion, none of which convincing), include:
(A) knowingly causes the transmission of a program, information, code, or command, and as a result of such conduct, intentionally causes damage without authorization, to a protected computer;
(B) intentionally accesses a protected computer without authorization, and as a result of such conduct, recklessly causes damage; or
(C) intentionally accesses a protected computer without authorization, and as a result of such conduct, causes damage and loss.
where computer is defined as:
(1) the term “computer” means an electronic, magnetic, optical, electrochemical, or other high speed data processing device performing logical, arithmetic, or storage functions, and includes any data storage facility or communications facility directly related to or operating in conjunction with such device, but such term does not include an automated typewriter or typesetter, a portable hand held calculator, or other similar device;
and where protected computer is defined as:
(2) the term “protected computer” means a computer— (A) exclusively for the use of a financial institution or the United States Government, or, in the case of a computer not exclusively for such use, used by or for a financial institution or the United States Government and the conduct constituting the offense affects that use by or for the financial institution or the Government; (B) which is used in or affecting interstate or foreign commerce or communication, including a computer located outside the United States that is used in a manner that affects interstate or foreign commerce or communication of the United States; or (C) that— (i) is part of a voting system; and (ii) (I) is used for the management, support, or administration of a Federal election; or (II) has moved in or otherwise affects interstate or foreign commerce...
Finally, civil remedy is authorized:
(g) Any person who suffers damage or loss by reason of a violation of this section may maintain a civil action against the violator to obtain compensatory damages and injunctive relief or other equitable relief.