Comparison

LumaLink vs Letter Explainer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

LumaLink

Features
Read full description

LumaLink turns your iPhone into a versatile light: by a tap, automatically as you approach, conveniently from your Apple Watch, or as a light show for the party. Whether at the campsite, on a night walk, as an outdoor night light, in your camper van, during a power outage or while reading in the tent: LumaLink gives you light exactly when you need it, with no fumbling in the dark. HIGHLIGHTS • Flashlight with stepless brightness and a smooth fade • Remote control from your Apple Watch: on/off and dimming right from your wrist • Auto light on approach: using Ultra Wideband, LumaLink notices when you come closer with your watch and turns the light on automatically, and off again when you leave • Lock mode: a black screen that protects against accidental taps. Unlock with 5 taps, a long press, or from your Apple Watch • Power saver: screen fully dark, the light stays on • Pair several iPhones and use them together as lamps SCREEN LIGHT When the LED is not the right tool, the screen itself becomes a lamp: • Warm light for reading and as a night light • Daylight for selfies, make-up and video calls • Red light that keeps your night vision: for camping, fishing and stargazing • Candle and campfire with a calm, natural flicker SIGNAL & SOS • Morse SOS, beacon and fast strobe • The LED flashes, the screen stays calm EVERY DAY • Sleep timer: the light turns itself off after 5 to 120 minutes • Battery guard: shuts down before the battery runs out • Nightstand light: lying on its side while charging, LumaLink shows a clock and glows dimly • Siri, Shortcuts, Lock Screen widget, Control Centre and the Action button DISCO MODE Turn one or more iPhones into a light show: • Flashes to the beat of your music, detected live via the microphone, or by tap tempo/BPM • Light patterns: All, Chase, Alternate or Random • Choose which iPhone runs the show (host), the others flash along automatically (guests) • Arrange several iPhones freely and tap one to identify it with an LED flash • Start and stop the disco right from your Apple Watch EVENTS (organizer option, subscription) A light show where the whole room flashes along: • Far beyond 8 iPhones: every iPhone that joins takes in more devices itself • Everyone flashes on exactly the same beat, even across several levels • Poster with QR code to print or share • Guests join with one tap, free and without pairing • Music detection finds the beat and passes it on to everyone GREAT FOR Camping & tents Ā· parties & celebrations Ā· events & concerts Ā· outdoor night light Ā· camper van Ā· garden evenings Ā· power outages Ā· workshop & basement Ā· night walks with the dog LumaLink uses only your devices' hardware: no account, no cloud, no data sharing. Note: auto light on approach needs an iPhone 11 or newer and an Apple Watch Series 6 or newer with Ultra Wideband. Disco mode and events with music detection use the microphone. Caution: strobe light, not suitable for people with photosensitivity or epilepsy. ORGANIZER SUBSCRIPTION The organizer option is available monthly or yearly, with one week free for new subscribers. The subscription renews automatically unless cancelled at least 24 hours before the end of the period and can be cancelled at any time in your Apple Account settings. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://smart-idea.net/datenschutz.html

About

Letter Explainer

Features
Read full description

A letter from the tax office, your health insurer, a debt collector or the city – and you don't understand a word? Letter Explainer photographs the letter and tells you in three plain sentences what it says, what the sender wants and by when you need to act. How it works 1. Photograph the letter or share a PDF. 2. Read the plain-language version: who is writing, what they want, whether you must act. 3. Put the deadline in your calendar with one tap – with reminders so nothing slips. What makes Letter Explainer different - Explanations in your language: English, German (simple), Turkish, Arabic, Ukrainian, Russian, Polish, Romanian, Spanish, French, Portuguese, Italian. - Deadline guard: the app spots phrases like "within one month of notification", works out the date and shows you how. - "If you do nothing": see right away what happens if the letter stays on the pile. - Amount, IBAN and reference ready to copy – pay a reminder in a minute. - Archive with search: every letter in one place, ticked off when done. - Share the result with family instead of asking them for help. Privacy first On iPhones with Apple Intelligence the analysis runs entirely on device. If your iPhone doesn't support it, the app asks before sending the text – with names, addresses and bank details masked – through our server. Nothing is stored. No account, no ads, no tracking. For families Set up Letter Explainer for your parents: large text, one language, one button. The yearly plan covers the whole family through Family Sharing. Pricing 3 letters free. Then €19.99 per year or €3.99 per month. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the period. Manage or cancel in iOS Settings. Letter Explainer explains letters. It is not legal advice. If in doubt, contact an advice centre. Privacy: https://mg.support/de/brief-erklaerer/datenschutz Ā· Terms: https://mg.support/de/brief-erklaerer/agb

Screenshots

LumaLink4 screens
Letter Explainer4 screens

Verdict

The call

The clearest difference is update cadence: Letter Explainer at daily against LumaLink's weekly. On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price Ā· Rating Ā· Positive reviews Ā· Number of ratings Ā· Update frequency Ā· Ads Ā· In-app purchases Ā· Monetization Ā· Best chart rank Ā· Devices Ā· Requires iOS

CostPrice Ā· In-app purchases Ā· Ads Ā· Monetization

Both are free to download. LumaLink sells 1 one-off in-app purchase and Letter Explainer sells 2 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

LumaLink ships an update weekly, Letter Explainer daily. The most recent releases landed on October 25, 2026 and October 15, 2026 respectively.

Scorecard1 real difference Ā· 5 level
LumaLink versus Letter Explainer: the parameters behind the verdict, then further details
ParameterLumaLinkLetter Explainer
PriceFreeFree
Update frequencyWeeklyDaily — better
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, Apple Watch — betteriPhone
Requires iOS18.018.0
Further details — not scored
Size6 MB4 MB
Age rating4+4+
DeveloperSteve KnoeflerJochen Jasch

In-app purchases

1 purchases

LumaLink

One-time1
  • Full Version$1.99
2 purchases

Letter Explainer

Subscriptions2
  • Pro monthly$3.991 Month
  • Pro yearly$19.991 Year

Questions

Is LumaLink free?
LumaLink is free to download, with in-app purchases available.
Is Letter Explainer free?
Letter Explainer is free to download, with in-app purchases available.
Do LumaLink or Letter Explainer have ads?
Neither LumaLink nor Letter Explainer shows ads.
Which is updated more often, LumaLink or Letter Explainer?
LumaLink ships an update weekly, and Letter Explainer daily. Most recently, LumaLink was updated on October 25, 2026 and Letter Explainer on October 15, 2026.

Other comparisons