There was a question the other day on stackoverflow where someone was looking for help on the performance of a native IOS application they created that could not sync with QuickBase for some reason. I can't find it immediately but you might search there yourself.
However, it is quite possible to create a web application (not a native IOS/Android app) that works with QuickBase using nothing but QuickBase and a web technology called Service Workers. In fact this is the primary purpose of the Service Worker technology - to give web apps the same capabilities as installed native apps. This sentiment is expressing in this drawing from a popular Service Worker blog post: "Help! I want to be like an App":
Service Worker, what are you ?https://kosamari.com/notes/Service-Worker-what-are-you
In fact there are frameworks being developed for Service Workers to make creating web apps very simple. As applied to QuickBase it should be pretty simple to create web apps through code pages and the QuicikBase API that display reports and accept the creation of record while offline and automatically sync with the QuickBase servers when network connectivity is regained. I will be covering them later in my Service Worker Travel Log.