After the "OAuth dance" is complete the request is never sent back to the app. I didn't have this happen with UIWebViews.

SchemeRedirect.m

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    
    RTVLog(@"decidePolicyForNavigationAction %@", navigationAction);
    
    if (navigationAction.navigationType == WKNavigationTypeOther) {
        
        NSURL *url = navigationAction.request.URL;
        UIApplication *app = [UIApplication sharedApplication];
        
        if ([[url scheme] isEqualToString:RabbleURLScheme]) {
            
            if ([app canOpenURL:url]) {
                [app openURL:url];
            }
        }
        
    } else if (navigationAction.navigationType == WKNavigationTypeLinkActivated) {
    
        NSString *url = navigationAction.request.URL.absoluteString;

        self.goBackButtonItem.enabled = [url rangeOfString:__loginURL].location == NSNotFound ? YES : NO;
        self.goBackButtonItem.title   = NSLocalizedString(@"Back", nil);
    }
    
    decisionHandler(WKNavigationActionPolicyAllow);
}