public Dictionary<string, UIImage> GetImages(string directory) {
  var images = new Dictionary<string, UIImage>();
  var paths = Directory.EnumerateFiles(directory, "*.png");
  foreach (var path in paths) {
    images[path] = UIImage.FromFile(path);
  }
  return images;
}

public async Task<List<FeedItem>> GetFeedItems(DateTime date) {
  var feed = "http://planet.xamarin.com/feed/";
  var response = await httpClient.GetStringAsync(feed);
  var items = await ParseFeedAsync(response);
  return items.Where(item => item.Published.Date == date).ToList();
}