SpamBuster app icon

Your phone, ringing only for people who matter.

SpamBuster screens every incoming call against rules you control — entirely on your device. Your calls and numbers never leave your phone.

Download on Google Play

Free · Android 10+ · No internet permission

Why SpamBuster?

Six reasons people switch.

100% on-device & private

SpamBuster has no internet access at all. Your calls, numbers, and contacts never leave your phone. Nothing is uploaded, tracked, or sold.

You set the rules

Every filter is opt-in and tunable. SpamBuster does exactly what you tell it to, nothing more.

Block hard or flag soft

Reject unwanted calls silently, or let them ring with a "Suspected spam" warning so you can decide. Your choice, per rule.

Transparent

A full call history shows every blocked, flagged, and allowed call — with the reason it was matched. No surprises.

Quiet and automatic

Once set up, it works in the background. Your phone only rings for calls that pass your rules.

Lightweight & focused

A single-purpose tool, not a bloated "security suite." It does one thing, and does it well.

How It Works

Three outcomes. Zero complexity.

When a call comes in, SpamBuster checks it against your active rules in a fraction of a second and picks one of three outcomes:

Call screening outcomes
Outcome What the caller experiences What you experience
Allowed Call rings normally Your phone rings as usual
Soft-flagged Call still rings through Phone rings + a "Suspected spam" notification
Hard-blocked Silently rejected — they hear voicemail or a busy tone Phone stays silent; call is logged
Soft = "let it through, warn me"

Good for filters you're not 100% sure about (e.g. unknown callers), so you never miss a real call.

Hard = "don't even ring"

Good for filters you trust completely (e.g. known spam prefixes, your personal blacklist).

Every Feature

All the tools, none of the bloat.

Personal Blacklist

Add specific numbers you never want to hear from. The blacklist always hard-blocks and takes priority over every other rule — a blacklisted number is rejected, full stop. You can add a number straight from your call history.

Known Spam Number Prefixes

Phone regulators reserve certain number ranges for telemarketing. Legitimate callers never use these ranges, so they're safe to block outright. SpamBuster ships with curated, built-in spam prefixes — including ranges reserved by France's ARCEP for telephone canvassing. Toggle by country or by individual prefix. Defaults to hard-block.

Private / Withheld Numbers

Block callers who hide their caller ID. When this filter is on, calls with no visible number are hard-blocked.

Not in Contacts

Block or flag calls from any number that isn't saved in your contacts. Calls from people you know are never blocked by this filter. Only active if you grant contacts access — SpamBuster skips it gracefully otherwise.

International / Foreign Calls

Block or flag calls coming from outside your home country. Your home country is always allowed. Add per-country exceptions for specific foreign countries you do expect calls from, or set individual countries to their own soft/hard treatment.

Call History

A complete, on-device log of every screened call: the number, the caller's name if they're a contact, the time, the outcome, and the rule that triggered it. Tap an entry to add the number to your blacklist. Configurable retention: 1 day, 7 days (default), 30 days, 90 days, 1 year, or forever.

"Suspected Spam" Notifications

Because Android gives screening apps no in-call label, soft-flagged calls trigger a heads-up notification so you can recognise a likely spam call while it's still ringing.

Zero Data. Zero Risk.

SpamBuster cannot send data off your device, by design.

Your calls, contacts, and blacklist are stored only on your phone. There is literally no network access in the app.

Getting Started

SpamBuster guides you through a short setup — takes under a minute.

  1. Welcome

    SpamBuster explains what it does and makes its privacy promise: your data stays on your device, always.

  2. Permissions

    Grant phone access (required). Contacts and notifications are optional — SpamBuster works without them.

  3. Enable call screening

    Choose SpamBuster as Android's call screener. Android will prompt you directly.

  4. Home country

    Tell SpamBuster your home country so it can distinguish local from foreign numbers.

  5. Choose what to block

    Flip on the filters you want and pick soft or hard for each one.

  6. Done

    A summary of what's now protecting you. Everything chosen during setup can be changed anytime in Rules and Settings.

Requires Android 10 (API 29) or newer.

Questions

Common questions, straight answers.

Does SpamBuster send my calls or contacts anywhere?
No. The app has no internet access at all. Everything happens on your phone.
What happens to a blocked caller?
A hard-blocked call is silently rejected. Depending on your carrier, the caller hears your default voicemail greeting or a busy tone. They aren't told they were blocked.
Will I miss real calls?
You're in control. Use soft mode for any filter you're unsure about — those calls still ring, just with a warning. Your contacts are never blocked by the "Not in Contacts" or international filters, and your home country is always allowed.
Do I have to give it my contacts?
No. Contacts access is optional. Without it, SpamBuster simply skips the contacts-based filter rather than misfiring.
Is it free?
Yes. SpamBuster is free, with no ads and no in-app purchases.
Which calls does it screen?
Incoming calls. SpamBuster checks each one against your active rules as it arrives.
Can I see what it blocked?
Yes — the call history lists every allowed, flagged, and blocked call with the reason, kept for as long as you choose (default: 7 days).