User guide

Everything in Sayfarer, screen by screen. Five minutes to read, or jump to the part you need.

Getting started

Install Sayfarer from Google Play and open it. The welcome tour takes about a minute:

Your language. The language you want things translated into. Sayfarer suggests your phone's language.
Where you're going. Pick a destination and the app pre-loads its country hub, phrasebook and emergency numbers.
Gemini key. Paste your free key (see below). You can skip this and add it later in Settings.
Accessibility. Text size, high contrast, dyslexia-friendly font and reduced motion.
Microphone. Allow the microphone so the live translator can hear you.

The app has four tabs along the bottom: Translate, Explore, Learn and Saved. The red SOS button and the Settings cog sit at the top of every tab.

Your Gemini key

Live translation, photo translation, trip phrases, pronunciation scoring, role-play and AI voices run on Google's Gemini models. They need a free API key that belongs to you, so nothing ever passes through our servers.

Open aistudio.google.com/apikey and sign in with any Google account.
Tap Create API key. No card is needed.
Copy the key, open Sayfarer, go to Settings › Gemini API key, paste it and tap Save & test.

The key is stored encrypted on your phone. Remove key on the same screen deletes it. Google's free tier is generous for personal travel; if you ever hit a limit, the app tells you and waits.

Everything that doesn't need AI works without a key: phrasebooks, cultural tips, essentials, SOS cards, saved items, flashcards, quizzes and offline packs.

Translate

The language bar at the top shows Auto detect on the left and your language on the right. Tap either to change it; tap the arrows to swap.

Live

Tap the mic to start continuous listening. Sayfarer listens, detects the language, translates and speaks the result. Tap again to stop.
Hold the mic to talk push-to-talk style: it listens while you hold and translates when you let go.
Each result shows the detected language with a confidence badge. Tap the badge to correct the language if it guessed wrong.
On each card: speaker plays it again, star saves it to favourites, copy copies the translation. Long-press a card for more: add a note, move to a collection, share, delete.

Type

Switch to Type when it's too loud to talk. Type or paste, tap send, and the translation is shown and spoken.

Hearing-impaired mode

In Settings › Accessibility, this makes every status line and result larger and keeps them on screen, with haptic feedback instead of sounds.

Conversation mode

Open it from the Conversation button under the mic. The screen splits in two: the top half is flipped so the person opposite can read it, the bottom half is yours. Each half has its own Talk button and language, and both sides auto-detect. Tap the flip icon in the top bar to turn the whole screen for a side-by-side chat instead.

Audio files

The Audio file button imports a recording or voice message (MP3, M4A, WAV, OGG, OPUS, AAC, FLAC and most video files). You get the full transcript with its translation, split by speaker where possible, and can save or export it like any other translation.

Menus, signs and photos

The Photo button opens the camera or your gallery. Point it at a menu, sign, ticket, timetable or form.

Menus come back as a list of dishes with price, description and ingredients. Set your diet and allergies once in Settings › Dietary needs (vegan, vegetarian, halal, kosher, gluten-free, nut, lactose, shellfish) and every dish is flagged for you.
Say it pronounces the original dish name so you can order out loud.
Signs and documents are translated in full, laid out in reading order.

Explore

Search any of 250 countries or pick from the ones near you. Each country hub has four tabs:

Phrases: the phrasebook by category (greetings, dining, transport, shopping, hotel, health, emergency and more) and level (beginner to advanced), with pronunciation guides for non-Latin scripts. Twelve languages are built in; others are generated on first use and cached.
Guide: cultural dos and don'ts, tipping, etiquette and safety tips.
Essentials: local time, currency converter, calling code, driving side, plugs and the emergency numbers with call buttons.
Trip: tell it your interests (food, hiking, nightlife, museums, business…) and it writes a tailored phrase list you can save.

SOS

The red SOS button is on every screen and works with no signal. It opens the emergency numbers for the country you're in (set automatically from your destination, or pick another) with one-tap call buttons, plus full-screen cards in the local language: “I need a doctor”, “I'm allergic to…”, “Call the police”, “I'm lost” and more. Hold the phone up, or tap the speaker to have the card read aloud.

Learn

Flashcards: spaced repetition. Grade each card Again, Hard, Good or Easy and it schedules the next review.
Quiz: multiple choice, listening and typing rounds for any category.
Pronunciation: say the phrase, get a score out of 100, hear what the AI understood and read a tip for what to fix.
Role-play: scripted scenarios (restaurant, hotel, taxi, pharmacy, market, meeting someone) with an AI partner who replies to what you say.
Ambient: plays phrases on a loop while you pack, with the screen awake or off.
Goals, streaks and badges: set a daily minutes goal in Settings and keep the streak going.

Saved

Every translation lands in History automatically unless you turn that off in Settings. Star items to keep them in Favourites, and group them into Collections per trip. Search and filter by language, country, kind or date. Any list can be exported as PDF, CSV or text, printed, or shared.

Voices

In Settings › Voice & speech choose between:

Phone voice: your phone's own voices, free and offline. Pick the accent and gender per language, set pace and pitch.
AI voice: natural Gemini voices (needs a key). Choose a voice, a tone (friendly, formal, casual, calm), pace, pitch, playback speed and loop.

Try it plays a sample in the selected language so you can hear the difference before you commit.

Offline packs

Settings › Offline packs lists 59 languages. Each pack is about 30 MB and lets you translate typed and spoken text on your phone with no connection. Turn on Download on Wi-Fi only to save mobile data. When you're offline, Sayfarer switches to packs automatically and tells you so with a banner.

Settings and accessibility

Appearance: dark, light or system theme, high contrast, dyslexia-friendly font, text size up to 160%.
Motion and layout: reduced motion, one-handed layout (controls move to the bottom), haptics on or off.
Languages: your language, the default conversation partner language, and the register (formal or informal) used in translations.
AI model: choose Gemini Flash (fastest), Pro (most accurate) or Flash-Lite (lightest). Flash is the default.
Learning and travel: daily goal, dietary needs, interests.
Data: export history as CSV, clear history (favourites are kept), remove the key.

Your data

Sayfarer has no servers and no accounts. History, favourites, collections, learning progress and settings are stored on your phone only. When you use an AI feature, the audio, text or photo for that request goes from your phone directly to Google's Gemini API under your own key and Google's terms; we never see it. Uninstalling the app removes everything. Full details in the privacy policy.

Troubleshooting

“Add your free Gemini key” banner: the AI features need a key. See Your Gemini key.
Key test fails: check it was copied in full, with no spaces, and that the Google account has access to AI Studio in your country.
Mic does nothing: allow the microphone in Android Settings › Apps › Sayfarer › Permissions, then try again. Check nothing else is recording.
Wrong language detected: tap the confidence badge and pick the right one, or set the left language instead of Auto detect.
No sound: turn up the media volume, check Do Not Disturb, and in Voice & speech tap Try it. If a phone voice is missing, install it in Android Settings › System › Languages › Text-to-speech.
Offline pack won't download: check free space and the Wi-Fi-only switch.
Anything else: email concisewebdesign@gmail.com with your phone model and what happened. See the support page.