Why are you writing std::__1 ? I would say that that's undefined behaviour, unless you know something I don't.

I believe that the listings in the App Store are per-country. So if you are in a relatively small country, and you and a friend have each bought a copy, then that may be enough to get you to a good position in the list that you see. It may be possible to view other countries' App Store listings via some third-party websites. Also, beware that the App Store listings do not purely indicate sales volumes; positions in the lists include other factors.

Just use clang (or clang++). I've never heard of "GPP". Apple have their own version of clang, which differs slightly from the "upstream" clang. The easiest way to install gcc/g++ is to use Homebrew.

Yes, that should work.

That depends on whether your custom symbol is, in law, a "derived work" from Apple's copyright symbol. If you've taken an Apple symbol and make a small adjustment to it - for example, putting a / though their $ symbol, as you seem to have done in your example, then I'm sure that does count as a derived work and cannot be used. On the other hand, if your custom symbol is all your own work - and the only connection with Apple's symbols is, for example, that you've designed your symbol to look right when used in combination with the Apple symbols - then it probably is not a derived work, and can be used. If you're unsure, ask an intellectual property lawyer. Well, except that you would need a lawyer who is more expensive than Apple's lawyers, and that could be difficult to find.

I forget exactly how the questions are worded, but I believe that what you need for AppAttest doesn’t need the export compliance paperwork.

Yes, it’s sufficient but consider more RAM if you can afford it.

If you are not using in-app purchase, no commission is due to Apple.

It is the current exchange rate on the day when Apple makes the payment to you. So NO, you do not always get $0.70 in the scenario you describe.

Sure. But what do you want to happen? Why are you defining your own puts()?

a toy made in the 90s by a company called Bandai, and my app is a recording app for people who play with it Do you have Bandai’s permission for your app? If not, what is the legal basis for your use of their intellectual property?

What do you want to happen here? You have a function with the same name as a libc function to which address sanitiser intercepts calls. Do you want address sanitiser to intercept calls to your puts(), or not?

Wait until the copyright expires in 2040ish. Or, ask whoever owns the rights for permission and send the contract to Apple. Or, get an intellectual property lawyer to write an opinion saying you’re not infringing anything and send that to Apple. Fundamentally it sounds like whoever owns the rights to VPET has complained to Apple about copycat apps and now Apple filters them out. There have been a few similar cases. Apple will not attempt to arbitrate, they will just reject everything until there is no mention and no similarity.

You should ask the OpenVPN people for their thoughts. It is mostly OK to use GPL-licensed code in an iOS app store app. You obviously have to publish ALL of your source code and provide an offer to supply that to everyone who installs the app. “Mostly OK” isn’t quite enough, though. Two issues I’m aware of are: The minimum end users terms and conditions for app store apps ( https://www.apple.com/legal/internet-services/itunes/dev/minterms/ ) need to not conflict with the GPL terms. In particular: “The license granted to the End-User for the Licensed Application must be limited to a non-transferable license to use the Licensed Application on any Apple-branded Products that the End-User owns or controls …”. That “non-transferable” bit is clearly problematic. The GPL requires that you supply the source code, and says: “The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable.”. It could be argued that the “installation of the executable” part is not achievable for iOS because regular users cannot install executables onto their devices. (Though actually they can, now, without paying a developer programme membership, with some limitations.) As I said, ask the OpenVPN people what their policy is. If the copyright holders don’t object to what you plan to do, then minor infractions are less of a concern. But I know they do also offer commercial licensing terms. If they feel that iOS apps should be using their commercially-licensed product, you need to be much more cautios (i.e. talk to a lawyer).

What is “VPET”? Does your app resemble it?