SMS Tech

Private SMS / MMS app with voice messages, encrypted vault, biometric unlock.

Repo:	F-Droid.Org
AppID:	com.filestech.sms
Author:	Patrice Haltaya
License:	Apache-2.0
Donation:	Webpage
InRepoSince:	2026-10-27
LastRepoUpdate:	2026-11-11
LastAppUpdate:	Unknown
LastVersion:	1.30.0
Categories:	Phone & SMS
APK source:
Google Play:	Check if it's there

SMS Tech is an ad-free, tracker-free SMS / MMS app for Android. It replaces the stock messaging app while keeping every message on your device — no cloud, no analytics, no third-party SDK shipping your data anywhere.

Features

SMS and MMS — full default-SMS-app support on Android 8 (API 26) through 15+

Voice messages — push-to-talk recording sent as a real MMS, capped at 120 s / 280 KB so every carrier accepts it

Encrypted vault — hide sensitive conversations behind SQLCipher, with the key wrapped in the Android Keystore. Toggle "Lock vault on leave" to re-lock it every time the app goes to background

Decoy PIN — a second PIN that opens the app in a decoy view where the vault stays invisible and inaccessible

Emergency mode — hold the button for 3 s to send an alert SMS to your Safety Call contacts, with a single GPS fix if you granted location; without that permission the SMS still goes out, only without coordinates. Quick access to the emergency numbers of the country your phone is connected to, and shortcuts on the lockscreen notification. The emergency numbers open in the Phone app, ready to call: Android lets only it call them directly

Biometric unlock — fingerprint or face, with a PIN fallback you set yourself

Contextual reply — long-press a message, pick "Reply" and your composer shows a mini-quote so the recipient sees what you are answering

Delegated translation — long-press a message and pick "Translate" to hand the text to whichever translation app you have installed (Google Translate, DeepL, Aves Translate …) through a system Intent. No translation model is bundled, and SMS Tech itself sends nothing anywhere

Scheduled messages — write an SMS, pick a date and time, and it is sent at that moment even if the app is closed

OS-wide blocked numbers — at first launch, SMS Tech mirrors the system blocklist (Phone app, Samsung Messages) and retroactively deletes the conversations that match; a conversation you block moves to its own folder

Attachment picker — Photo, Video, File, Contact card. Photos are automatically re-encoded as JPEG to fit MMS carrier caps. Tap a photo to view it in the app (zoom, animated GIFs)

Full-text search across every conversation, with FTS4 indexing

Export a conversation as a PDF for archival

Encrypted local backup using a passphrase distinct from your unlock PIN

Themes — Light / Dark / AMOLED / "Dark Tech" slate-blue accent

English, French, German, Italian and Spanish UI

Confirmation toggle in Settings → Send → "Confirm before send" requires a confirmation dialog before any SMS, MMS or attachment is dispatched

Privacy

No analytics, no crash reporters, no third-party tracking SDK

No network access: SMS Tech does not hold the Internet permission; Android's own MMS service carries MMS. Nothing but your messages leaves the phone

Location and phone-call permissions serve Emergency mode only. Both are opt-in, neither is ever used in the background, and the app works without granting either

Apache License 2.0 — source code at https://github.com/gitubpatrice/SMS-TECH

Security model documented at https://github.com/gitubpatrice/SMS-TECH/blob/main/SECURITY.md

Project home: https://files-tech.com/sms-tech.php

WhatsNew:

Group chats copied from your previous app stay groups. Verizon and Visible: incoming MMS are fetched the way their servers expect. Pictures up to 4 MiB arrive; a failed MMS is explained, with Android's error code. Group MMS show who they were sent to. Photos open in the app (zoom, GIFs); a conversation's photos and videos in one place. Blocked conversations have their own folder. Copy a number from conversation details. Emergency tiles open the Phone app. Outgoing MMS follow Android's format.

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