CIOAPISession *session = [[CIOAPISession alloc] initWithConsumerKey:@"your-consumer-key"
                                                     consumerSecret:@"your-consumer-secret"];

[[session getMessagesWithParams:nil]
 executeWithSuccess:^(NSArray *responseArray) {
     self.messagesArray = responseArray;
 } failure:^(NSError *error) {
     NSLog(@"error getting messages: %@", error);
 }];

[[session updateFoldersForMessageWithID:message[@"message_id"]
                                 params:@{@"add": @"Test Label"}]
 executeWithSuccess:^(NSDictionary *response) {
     NSLog(@"Response: %@", response);
 } failure:^(NSError *error) {
     NSLog(@"error moving message: %@", error);
 }];

// 0 is an alias for the first source of an account
[[session getFoldersForSourceWithLabel:@"0" params:nil]
 executeWithSuccess:^void(NSArray *folders) {
     NSLog(@"Folders: %@", folders);
 } failure:^void(NSError *error) {
     NSLog(@"Error getting folders: %@", error);
 }];

NSDictionary *file = [message[@"files"] firstObject];
CIODownloadRequest *downloadRequest = [session downloadContentsOfFileWithID:file[@"file_id"]];
// Save file with attachment's filename in NSDocumentDirectory
NSURL *documentsURL = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory
                                                              inDomains:NSUserDomainMask] lastObject];
NSURL *fileURL = [documentsURL URLByAppendingPathComponent:file[@"file_name"]];
[session downloadRequest:downloadRequest
               toFileURL:fileURL
                 success:^{
                     NSLog(@"File downloaded: %@", [fileURL path]);
                 }
                 failure:^(NSError *error) {
                     NSLog(@"Download error: %@", error);
                 }
                progress:^(int64_t bytesRead, int64_t totalBytesRead, int64_t totalBytesExpected){
                    NSLog(@"Download progress: %0.2f%%",
                          ((double)totalBytesExpected / (double)totalBytesRead) * 100);
                }];