DAF Jammer

Experiment with Delayed Auditory Feedback (DAF) to jam speech.

Sagebrush Systems Inc · com.sagebrush.stfu

Not rated yet 10K+ downloads v20 2.4 MB Android 5.0+ PEGI 3 · Everyone

Download APK 2.4 MB All versions

Signature matches the Google Play version Details

At a glance

Latest version: v20 (20)
Updated: Nov 8, 2025 (11 months ago)
APK size: 2.4 MB
Requires: Android 5.0+ (API 21)
CPU support: Any (no native code)
Category: Music & Audio (app)
Listed since: Nov 16, 2021 (at least)
Permissions: 11 (2 sensitive)
Website: sagebrush.com
Developer contact: [email protected]
Privacy: Developer's privacy policy

About this APK

DAF Jammer is an app by Sagebrush Systems Inc in the Music & Audio category, listed since at least November 2021. It has no native code, so it runs on any Android processor.

Since version 15, the minimum Android version rose from 4.0 to 5.0. It asks for 11 permissions, 2 of them sensitive: record audio and Bluetooth connect. It asks for the same permissions as version 18. The app offers in-app purchases through Google Play.

What's new in v20

Fix timeout system error in service (background operation)

Description

From the listing uploaded by “appupdater”.

This app is useful for experimenting with the phenomenon of Delayed Auditory Feedback (DAF) to disrupt speech. DAF might have other uses, involving speech therapy or practicing speeches that will be presented in large venues where echoes are a problem. The app is currently currently targeted for Android devices with built-in echo cancellation abilities, such as smart phones that support speakerphone features. If you run on a tablet, which typically does not implement echo cancellation, use headphones to prevent runaway audio feedback. Controls include volume and delay. Adjust the volume to prevent runaway feedback. Adjust the delay for optimal disruption of talking. We find that 150 milliseconds works pretty well. For best results, the phone should be placed as close to the subject's head as practical. No ads, free, fully functional. Voluntary contribution suggested via in-app billing, with no nags.

Version history

3 versions are listed, going back to v15. Since v18 it requires Android 5.0+.

v20 LATEST Nov 8, 2025 2.4 MB TRUSTED v18 Sep 2, 2024 2.4 MB TRUSTED v15 Jun 10, 2024 2.5 MB TRUSTED

All 3 versions

Security & authenticity

Security rating: Trusted

Signing certificate

Signature matches the Google Play version Checked by the source store on Nov 8, 2025.
Certificate issued to “Sagebrush Systems Inc” This is the certificate of the Google Play version.
Same certificate as the 2 other versions checked

Store checks and file details

Developer signature verified Nov 8, 2025
Validated against Google Play Nov 8, 2025
Signed byCN=Jim Sells, OU=president, O=Sagebrush Systems Inc, L=Lemitar, ST=NM, C=US
Signing certificate (SHA-1)06:AA:C5:53:C4:01:AF:DA:7A:11:B4:1B:83:0D:25:B9:24:A3:D0:CF
File MD54950933f99d967ee26f99c69c969e8fb
Uploaded by “appupdater” Gold tier · 117,810 followers · uploading since 2020

Scans and ratings come from the source store; the certificate comparisons are AAPKs's own, made from the files' published signatures (2 other versions compared). AAPKs doesn't scan files itself — compare the MD5 and signer after downloading.

Permissions (11)

DAF Jammer requests 11 permissions, 2 of them sensitive.

Bluetooth connect Sensitive android.permission.BLUETOOTH_CONNECT
Record audio (microphone) Sensitive android.permission.RECORD_AUDIO
Foreground service media playback android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK
Foreground service microphone android.permission.FOREGROUND_SERVICE_MICROPHONE
Full network access android.permission.INTERNET
In-app purchases (Google Play Billing) com.android.vending.BILLING
Internal broadcast protection (app-defined) com.sagebrush.stfu.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Modify audio settings android.permission.MODIFY_AUDIO_SETTINGS
Run foreground services android.permission.FOREGROUND_SERVICE
Show notifications android.permission.POST_NOTIFICATIONS
View network connections android.permission.ACCESS_NETWORK_STATE

Required hardware & features

Bluetooth android.hardware.bluetooth
Basic touch input android.hardware.faketouch
Microphone android.hardware.microphone

DAF Jammer APK: questions and answers

Is there a version of DAF Jammer for older Android phones?

The current version needs Android 5.0 or later. Version 15 is the newest listed build that installs on Android 4.0 and later. It is an old build: apps that rely on online services may no longer connect when they are this old. Get version 15 · All versions

Can I install this APK over the version I already have?

Yes, if your installed copy is older. It is signed like the Google Play version, so Android installs it as an update and keeps your data.

Is DAF Jammer free?

The APK is free to download, but the app offers in-app purchases through Google Play.

Is the DAF Jammer APK safe?

No one can promise that a file is safe, but some things can be checked. The source store rates this file Trusted. Its signature matches the Google Play version. It is signed with the same certificate as the 2 other versions checked. After downloading, check that the file's MD5 is 4950933f99d967ee26f99c69c969e8fb.