As far as I know, apps can only load libraries that are a part of iOS or that came with the app. This is based on the code signature, and not on the framework location. (For example, you can copy one of Pythonista's internal frameworks and load the copy without any issues using ctypes.) It's not possible to load frameworks that were signed for a different app. (For example you cannot copy a Pythonista framework to Editorial, even though both apps are from the same developer.) Frameworks that you compiled yourself using Xcode cannot be loaded either, even if you sign them with a development certificate. (The exception to that is @omz himself when using a dev build on Pythonista, because that is also signed with the dev cert. I remember there was a conversation about that on Twitter a while back, where omz could load a dev-cert-signed framework, but others couldn't.)
Welcome!
This is the community forum for my apps Pythonista and Editorial.
For individual support questions, you can also send an email. If you have a very short question or just want to say hello — I'm @olemoritz on Twitter.