Will Apple eject this app from their web store for downloading code? Maybe not. Current Apple policy:

2.5.2 Apps should be self-contained in their bundles, and may not read or write data outside the designated container area, nor may they download, install, or execute code, including other iOS, watchOS, Mac OS X, or tvOS apps.

Older policy:

3.3.2 — An Application may not itself install or launch other executable code by any means, including without limitation through the use of a plug-in architecture, calling other frameworks, other APIs or otherwise. No interpreted code may be downloaded or used in an Application except for code that is interpreted and run by Apple’s Documented APIs and built-in interpreter(s).

Apple once prohibited a Commodore 64 emulator because it had a BASIC intepreter. But they've lightened up a bit.