The LumaGrid Booth app

What you need

• An Android tablet (Android 7 or newer) with a front camera. A phone works for trying it out.
• Wi-Fi at the venue. If it drops, photos are saved on the tablet and upload by themselves when it's back.
• A screen lock PIN on the tablet, so only you can close the booth.
• Your event code and keyword, from your booking confirmation.
• Optional: a tablet stand and a ring light.
• Optional, for voice messages: a prop mic (a Bluetooth headset or handset mic, or a mic plugged into the headphone socket). Without one, the tablet's own mic is used. A Bluetooth mic keeps the charging socket free.

Install

1. On the tablet, sign in to your LumaGrid dashboard and tap 📱 Booth app. (Or download it on a computer and send the file to the tablet.) The download link works for 10 minutes.
2. Chrome may say "This type of file can harm your device". It says this about every app that does not come from Google Play. Tap Download anyway. Until you answer, the download shows as "pending".
3. Open the downloaded file. If Android asks, allow your browser or Files app to install unknown apps; this is only needed for apps from outside Google Play.
4. If Google Play Protect warns that the app is unknown, tap More details → Install anyway.
5. Tap Install. The app appears as Booth by LumaGrid.

Updating: download the new version from your dashboard and install it over the top. Your sign-in and settings stay. Delete old LumaGrid-Booth files from Downloads first: it frees space and stops Chrome thinking it already has the file. To see which version is on the tablet, hold the top-right corner, enter the PIN and open Start-up check: the title shows it.

First start

1. Allow the permissions it asks for: Camera (photos) and Location (records where the booth is and keeps it on the venue Wi-Fi); on older tablets also Storage (to save support reports). The Microphone is asked for once: the first time you sign in to an event with voice messages switched on. Choose While using the app (not "Only this time"). Once allowed, it stays allowed. You can also allow it in advance: Settings → Apps → Booth by LumaGrid → Permissions → Microphone → Allow.
2. Screen pinning keeps guests inside the booth. In the tablet's Settings, search for Screen pinning, turn it on, and turn on Ask for PIN before unpinning.
3. If the booth shows "The booth isn't fully locked", it tells you which of these is missing. The booth still works meanwhile.

Before the event: screen, sleep and battery

• Practise before your first event. Use your free trial event: sign in, take a photo, scan the QR code, leave a message and run Test it, then sign out. A booth can sign in to a real event from the start of its event day. On the day, run Test it before guests arrive: it keeps nothing. Do not leave a test message at a real event: it goes to the organiser.
• Keep the tablet plugged in. The booth keeps the screen on while it's open. If the battery drops to 5%, it lets the screen turn off to save power.
• Screen timeout: no need to change it, the booth keeps the screen awake. If it still goes dark, set Settings → Display → Sleep to the longest time.
• Keep the tablet's lock screen and PIN. The PIN is what stops guests closing the booth. If the tablet restarts or loses power mid-event, unlock it once with the PIN and the booth opens again by itself, still signed in if it's back within 15 minutes, or at any time during your booth hours.
• Stop Android closing the app: turn off Battery saver, and let the booth run in the background. On Huawei: Settings → Battery → App launch → Booth by LumaGrid → Manage manually, with everything on. On other tablets: Settings → Apps → Booth by LumaGrid → Battery → Unrestricted.
• Turn on Do not disturb so notifications don't pop up over the booth, and don't start a system update on the day.
• Free space: keep at least 2 GB free. Photos taken without internet are kept on the tablet until they upload. How many fit depends on the tablet's camera (newer tablets take bigger photos), so the booth works it out from its own photos and warns you when space runs low.
• No internet at the venue? Sign in to your event before you lose signal (a phone hotspot is fine) and keep the app open. Get the tablet online within 4 days of the event so the photos upload, and don't uninstall the app or clear its storage until they have. Until then they stay inside the booth app: they don't appear in the tablet's own Gallery, and once they upload they go through the same automatic photo checks as every other photo.
• Voice messages on? Connect and charge the prop mic, then run Test it before guests arrive (see Voice messages).
• Use a tablet just for the booth if you can. Other apps' notifications, alarms, calls and updates can pop up over the booth. The booth reminds you when Do not disturb is off.

Running the booth

• Start: enter your event code and keyword and tap Start booth.
• Booth hours (optional): set your event's start and end times when you book, or later on the Events page. Start the booth as usual with your event code and keyword. From then on, during your booth hours and for an hour either side, the booth stays signed in through a Wi-Fi drop or a power cut. If the tablet loses power or restarts, switch it back on and open the app if it doesn't start by itself. There's no need to re-enter the event code. Without booth hours, this only works if the booth is back within 15 minutes; after that it asks for the event code and keyword again.
• Guests tap the screen, smile for the countdown, and scan the QR code to save their photo. The code stays up for up to 3 minutes and the booth returns to its start screen when they walk away.
• Close the booth: hold the top-right corner, enter the tablet's PIN, and choose Exit App. This signs the booth out, so next time enter your event code and keyword again.
• Switch event or sign out: hold the top-right corner, enter the tablet's PIN, and choose Sign out of this event. The booth is free for another tablet straight away.
• One booth per booking. If you see "A booth is already running for this event", close it on the other device first (Exit App or Sign out of this event). A booth that loses power keeps its place for 15 minutes so it can carry on.
• No internet: guests can still take photos, but they won't get a QR code. The screen shows "Saved!" and the photo goes into the event gallery once the booth is back online. The banner at the top shows how many photos are waiting. To upload them on another Wi-Fi or a phone hotspot, hold the top-right corner, enter the tablet's PIN, choose Open Android Settings, join the other network, then go back to the booth. Before you pack up, check the banner has gone: that means every photo has uploaded. If the tablet starts without internet, the booth still opens, or shows "No internet connection" and starts by itself once it's online.

Voice messages

Guests can leave a short spoken message for the organiser, then pose for a photo. The message stays with that photo. Only the organiser hears it: it never appears in the gallery or on a screen, and you cannot play it.

• Switch them on: voice messages are off unless you switch them on, one event at a time. On your Events page, open the event and turn on Voice messages at the booth. The page then shows how many messages have been left.
• The microphone: the first time you sign in to an event with voice messages, the tablet asks for the microphone: allow it. The booth then shows which mic messages will use: a Bluetooth mic if one is connected, otherwise a plugged-in mic, otherwise the tablet's own. Pair a Bluetooth mic once in the tablet's Bluetooth settings, and charge it before the event: the tablet cannot see its battery.
• Test it before guests arrive: hold the top-right corner, enter the PIN, choose Message mic, then Test it. Keep talking into the mic until the box closes (up to 30 seconds). A line ending "through the Bluetooth mic" with sound means your prop mic works, and the booth will remember that way for that mic. If no line hears it, that tablet cannot use that mic: use a plugged-in mic, or the tablet's own.
• What guests see: they tap Leave a message, then Record. While the mic gets ready, the mic is crossed out and the screen says "Getting the mic ready…". A big green tick means it is recording. They talk for up to 30 seconds, then choose Listen, Try again or Keep it, and pose for their photo. Nothing is kept unless they press Keep it.
• The mic sign, top left: a plain mic means messages are on and the mic is working. A red, crossed-out mic means the prop mic stopped sending sound or disconnected: messages will now use the inbuilt mic, so guests can carry on. Check it is on, charged and not muted. Tap the sign to see the warning again.
• Your part (Platform Agreement, Schedule 3, clause 8): tell guests at the booth, before they record, that their message goes to the organiser only, with a link to your privacy notice (the booth screen also says this). Tell your client, in your own terms, that messages are for their personal use, and that they should ask a guest before sharing that guest's message more widely. Messages come with the organiser's album download and are deleted with the event's photos.

Troubleshooting

The download says "pending" or "harmful"

Answer Chrome's warning: tap Download anyway. If Google Play Protect warns, tap More details → Install anyway. The download link works for 10 minutes: if it has run out, get a new one from your dashboard.

"App not installed"

If you sent the file to the tablet over Bluetooth, it can arrive damaged: download it on the tablet instead. Otherwise an older or differently signed copy is on the tablet (including test versions): in Settings → Apps, uninstall Booth by LumaGrid, then install again. If it still fails, restart the tablet and check it has at least 500 MB free.

The permission questions don't appear

Some tablets skip them. Hold the top-right corner, enter the PIN, choose Open Android Settings, then Apps → Booth by LumaGrid → Permissions, and allow them there.

"The camera is busy"

Wait a moment and tap again. If it keeps happening, close the booth (Exit App) and open it again.

A guest's phone won't read the QR code

Some older phone cameras struggle. Ask them to try their camera app, or another phone. Every photo is in the event's album either way.

A red, crossed-out mic at the top left

The prop mic is not sending sound, or it disconnected. Messages will now use the inbuilt mic, so guests can carry on. Check the prop mic is on, charged and not muted, then hold the top-right corner, enter the PIN and choose Message mic → Test it.

Anything else

Hold the top-right corner, enter the PIN and choose Start-up check: it shows what the app did last. Tap Save report: it saves a text file to the tablet's Downloads by itself. Email it, or send it over Bluetooth, to support@lumagrid.uk.

Open-source software

Booth by LumaGrid includes open-source software licensed under the Apache License, Version 2.0: AndroidX libraries and Material Components for Android (Google and the Android Open Source Project), and the Kotlin standard library and kotlinx coroutines (JetBrains). Licence text: apache.org/licenses/LICENSE-2.0.