NekoSMS

A pattern-based text message blocker for Android.

Requirements

• A rooted phone running Android 4.4 KitKat or newer
• Xposed framework

Features

• Works with all SMS apps, stock or third party
• Block messages based on sender and/or content
• Supports regular expressions, wildcard patterns, and more
• Backup and restore your filter rules across devices
• Free, both as in beer and in speech
• No internet access, no ads, no telemetry

Q&A

Why is it called NekoSMS?

No reason in particular. I wanted a name that had "SMS" in it, and "neko" was the first word that popped into my head. Hence, NekoSMS.

Why does this app require Xposed?

Starting from Android 4.4, only the default SMS app has the ability to intercept SMS messages. In order to bypass this restriction, code must be modified at the OS level.

What are the permissions used for?

• READ_SMS, WRITE_SMS for obvious reasons
• VIBRATE for notifications
• WRITE_EXTERNAL_STORAGE for importing/exporting backups

Does NekoSMS work with (insert SMS app here)?

As long as your ROM supports it, yes. There is no app-specific SMS blocking code, so if it works with one SMS app, it will work with them all.

How does it work? (for nerds)

It hooks the internal Android class, com.android.internal.telephony.InboundSmsHandler. This class is responsible for taking the raw SMS data received by the phone and dispatching it to the default SMS app, then broadcasting it to all apps capable of reading SMS messages.

Essentially, this app intercepts the data right before it is sent to the default SMS app, then runs it through the user-defined filters. If the message matches a blacklist rule, the broadcast is dropped.

How does it work? (for non-nerds)

Dragon magic.

Hey! Are you trying to steal my personal data?!

Does this look like the face of evil to you?

The code is fully open source, so feel free to check for yourself! :-)

Nyaa?

Nyaa!

License

All code is licensed under GPLv3. Icons are from Google's material icons library.