Is an IOS app that includes a binary file allowed on the AppStore?

I’m not seeing any red flags in the published guidelines.

• https://developer.apple.com/app-store/review/guidelines/

However, you have to make an app and submit it to TestFlight and then for sale to find out if your view of the app matches Apple staff view of it.

• https://developer.apple.com/documentation/storekit/skdownload/

If your app size is large, you may get rejected though for a variety of reasons (static analyzer flagging the app, app only downloads on WiFi, etc…).

If I were to read between the lines, it appears Apple wants to be the iOS code shipper and not take the place of providing your backend services for content distribution + code distribution. Unless you use in-app purchase to provision these binaries, your app should probably download these assets to local storage sandbox or use the files app to store the binaries. Shipping a new build just to change an embedded asset ties your hands more than it does Apple's hands. For a small enough app, it might not matter.

• https://developer.apple.com/wwdc15/214

I would use S3 buckets or another backend personally with on demand downloads so my app was cleaner to ship and review, but maybe your design is better for your needs. If the file is small and changes seldom, it won’t matter much initially.