type SetStateString = React.Dispatch<React.SetStateAction<string>>;
/**
 * Fetches and caches the favicon and manifest data for a given app domain.
 *
 * @param appDomain - The domain name of the app (e.g. "example.com").
 * @param setAppIcon - React setState function for updating the app icon URL.
 * @param setAppName - React setState function for updating the app name string.
 * @param DEFAULT_APP_ICON - A fallback icon URL to use if no valid favicon can be found.
 */
declare function fetchAndCacheAppData(appDomain: string, setAppIcon: SetStateString, setAppName: SetStateString, DEFAULT_APP_ICON: string): Promise<void>;
export default fetchAndCacheAppData;