SpamSMS is an iPhone application developed by Harjot Singh that aims to help users filter out unwanted SMS and MMS messages. With the use of Apple's CoreML Identity Lookup framework, the app identifies and blocks unwanted messages, allowing users to focus on the important ones.

One of the key features of SpamSMS is the ability to create custom rules based on keywords and numbers. Users can add their own keywords and numbers to override the incoming message and specify whether it should be filtered or not. This allows for personalized filtering criteria that can be easily enabled or disabled at any time.

The app boasts a clean and simple user interface, making it easy for anyone to understand and use. It also works offline, ensuring user privacy even without internet availability.

SpamSMS provides a built-in walkthrough to guide users through the setup process, including setting up the SpamSMS App Extension in the device's settings. Once set up, users can find filtered messages sorted in the "SMS Junk" list within the Messages app.

Please note that SpamSMS only works with SMS and MMS messages from unknown senders and does not filter messages from contacts or iMessage sources. Filtered messages have their notifications disabled and are sorted in the "SMS Junk" list of the Messages app.