Some interesting ways you might extend this project include:
- Create a do-it-yourself 'security system' to send you notifications when doors or windows are unexpectedly opened at home. Be alerted when a nosey sibling is going in your room!
- Use a load cell/scale to sense how much food is in the dish and send more accurate status messages.
- Create different SNS subscriptions such as HTTP endpoints (good for notifying other web services you build) or SQS queues (good for notifying other Amazon web services).
- Use the signature generation code in the sketch to call other Amazon web services, such as the S3 storage service.
Have fun adding notifications to your own Arduino projects!