Gatekeeper: SMS & Call Blocker

Filter spam texts by keyword. Block calls from numbers you add.

Gatekeeper is a text message filter and call blocker with rules you write yourself. Add the words, numbers and prefixes you do not want, and Gatekeeper silences the notification of every spam text that matches. Add phone numbers, and it rejects their calls. Texts are never sent to us.

WHAT YOU GET
• Your own rules: a keyword filter for spam texts. Silence texts by keyword, phone number or prefix (for example +44). Add as many rules as you need.
• Messages stay on your device: Gatekeeper never uploads your messages or your call history. Details of the small profile we keep for your installation are in our Privacy Policy.
• Call blocker (Android 10 or later): block numbers you add, entered as full numbers with country code, and Gatekeeper rejects their calls.
• Allowed list: add numbers, prefixes or sender names that Gatekeeper does not silence.
• Silenced: see who sent the notifications Gatekeeper silenced, with the time, how many and which kind of rule matched. The list stays on your phone for 30 days, shows at most 50 entries and never keeps message text. Tap Allow to add a sender to your Allowed list.

HOW IT WORKS ON ANDROID
Gatekeeper is an SMS filter that works on the notification, not on the message. As an SMS keyword blocker for the alert, it uses notification access to silence the notifications of spam texts that match your rules. The messages stay in your messaging app: Gatekeeper does not delete them, does not block text messages from arriving, does not need SMS permission and does not replace your messaging app.
Android grants this access to all notifications. Gatekeeper only reads those from messaging apps, on your device. The text of those notifications is not stored and not sent anywhere.
On Android 10 or later, choose Gatekeeper as your Caller ID & spam app. It then rejects calls from the numbers you added.

SET UP IN THREE STEPS
1. Open Gatekeeper and allow notification access when asked.
2. Add your first rule: a word, a number or a prefix.
3. To block calls (Android 10 or later), choose Gatekeeper as your Caller ID & spam app and add the numbers.

ON YOUR DEVICE
Gatekeeper checks your texts on your phone against your rules and, if you turn them on, the built-in word lists. Filtering works without an internet connection. No sign-up is needed, and there are no ads.

OPTIONAL SUBSCRIPTION PLANS
Pro is an optional subscription. It adds Smart matching and the AI filter to your SMS spam filter. Your own rules, the Allowed list and call blocking do not need a subscription.

THE AI FILTER AND SMART MATCHING (OPTIONAL, PRO)
The AI filter (Pro) is a spam text filter that checks messages against ready-made spam word lists in several languages, chosen and maintained by us and built into the app. It is keyword matching, not machine learning, and it works on your device. A word list can be wrong: a spam word can also appear in a message you want.
Smart matching (Pro) also catches common spelling variants of your words, such as with or without accents. It works for words written in Latin letters.
Both are optional. Turn either off at any time and filter only your own words.

GOOD TO KNOW
No filter is perfect: a rule can silence a message you wanted, so check your messaging app now and then. Call rules need a full number with country code (at least 7 digits). Short prefixes such as +44 work for texts only. A blocked call does not appear in your call log. Some Android versions can hide the content of notifications that look like codes. Gatekeeper may not see those, so they can arrive as usual. Number and prefix rules match when the notification shows the sender's number; a saved contact may appear by name instead.

Recent changes:
Fixes an issue where the AI filter could react to parts of ordinary words.