Amazon SNS FIFO topics are now available in AWS GovCloud (US) Regions

You can now use Amazon Simple Notification Service (Amazon SNS) FIFO topics in the AWS GovCloud (US) Regions in combination with Amazon Simple Queue Service (Amazon SQS) FIFO queues, to build applications that require messages to be sent and processed in a strict sequence and without duplicates. SNS FIFO is intended for customer use cases where it is critical to maintain the consistency in processing messages across multiple independent services in a strictly ordered manner. Example use cases include bank transaction logging, stock tickers, flight trackers, news broadcasting, inventory management, vote tabulation, and price updates.

Source:: Amazon AWS