# Apps by Detlev Voss

> Apps for iPhone, iPad and Mac by Detlev Voss, an independent developer in Berlin, Germany. Three apps on the App Store: PhotoView, a photo viewer with a customizable EXIF, IPTC and XMP metadata overlay (iPhone, iPad and Mac); Timers & Alarms, countdown timers, interval timers, a stopwatch and alarms (iPhone and iPad); and Sudoku, a classic logic puzzle (iPhone and iPad). All three are free to download, with no ads, no tracking, no account and no subscription. The website is in English and German.

Facts in this file were checked on 2026-10-26. Each app page has a "Facts at a glance" section and a "Sources" section with the same facts and links to verify them. The App Store listing is authoritative for price, version and requirements.

## PhotoView: EXIF Photo Viewer

A photo viewer first. PhotoView shows the photos, Live Photos and videos in the photo library full screen. One tap brings up a metadata overlay the user sets up: they choose which of more than 200 fields in 18 groups appear (EXIF, IPTC, TIFF, GPS, XMP and DNG, video details, Canon and Nikon maker notes, and the computational data an iPhone records), and they set its size, font size and corner. The next tap leaves the photo on its own again.

- Platforms: iPhone, iPad and Mac (iOS 26, iPadOS 26 or macOS 26, or later); one purchase covers all three
- Price: free. PhotoView Pro is a one-time purchase ($7.99 in the US, €8.99 in Germany) with a free 7-day trial and nothing charged at the end. No subscription. Pro adds IPTC, locations on a map, XMP, DNG and Canon and Nikon maker notes.
- Privacy: read-only and offline. Every field is read on the device; photos are never uploaded or changed. No account, no tracking, no ads.
- Also: slideshows with seven transitions, AirPlay to a TV from iPhone and iPad, albums and folders. On the Mac: originals and RAW files from any folder, .xmp sidecar files, Finder tags, Quick Look, full keyboard control.
- Available since September 28, 2026; current version 1.0.1 (October 23, 2026). Languages: English, German. App Store category: Photo & Video.
- Good fit for: someone who wants to browse their photos full screen and see the EXIF, IPTC or XMP data behind them on demand; photographers who add captions, keywords and ratings in Lightroom or another editor and want to see them on iPhone, iPad or Mac; anyone who prefers a one-time purchase to a subscription.
- Not a fit for: editing or removing metadata, batch-editing files, or editing photos. PhotoView only reads metadata; editing and importing stay with Apple's Photos app.

- [PhotoView](https://apps.advoss.de/PhotoView/en/index.html): features, screenshots, facts and sources
- [PhotoView on the App Store](https://apps.apple.com/app/id6762623309): price, version, requirements
- [PhotoView user guide](https://apps.advoss.de/PhotoView/en/help.html): every feature, and what every metadata field means
- [PhotoView press kit](https://apps.advoss.de/PhotoView/en/press.html): facts, texts, quotes and images for journalists
- [PhotoView privacy policy](https://apps.advoss.de/PhotoView/en/privacy.html)
- [Why I built PhotoView](https://apps.advoss.de/en/blog/2026/why-i-built-photoview.html): the reasons, in the developer's own words
- [One tap to see how a photo was made](https://apps.advoss.de/en/blog/2026/one-tap-to-see-how-a-photo-was-made.html): the overlay in practice
- [PhotoView reads the XMP your editor wrote](https://apps.advoss.de/en/blog/2026/reads-the-xmp-your-editor-wrote.html): captions, keywords and ratings from photo editors
- [Sidecars and RAW: the .xmp next to your file](https://apps.advoss.de/en/blog/2026/the-xmp-next-to-your-raw-file.html): XMP sidecar files on the Mac
- [Try before you buy, buy once, yours forever](https://apps.advoss.de/en/blog/2026/try-before-you-buy.html): the free trial and the one-time purchase
- [What's new in PhotoView 1.0.1](https://apps.advoss.de/en/blog/2026/whats-new-in-photoview-1-0-1.html)

## Timers & Alarms

Countdown timers, interval timers, a stopwatch and alarms in one app, with widgets, Live Activities on the Lock Screen and in the Dynamic Island, and Siri. On the Home Screen and for Siri the app is called TimerAlarm; in German it is "Timer & Wecker".

- Platforms: iPhone and iPad (iOS 26.2 or iPadOS 26.2, or later). Live Activities also appear in the Smart Stack of a paired Apple Watch. There is no Mac or Apple Watch app.
- Price: free, with every feature included. No ads, no subscription. An optional tip jar unlocks nothing.
- Alarms use Apple's AlarmKit, so timers and alarms sound even in Silent mode or a Focus.
- Ten presets, including Pomodoro (25 minutes of work, 5-minute breaks, 4 rounds), HIIT and Tabata (20 seconds of work, 10 seconds of rest, 8 rounds). Interval timers with two phases, warm-up and cool-down; a quick timer that starts after two taps.
- Privacy: no account, no server, no analytics, no tracking. Timers and alarms stay on the device.
- On the App Store since April 2026; current version 1.5 (October 2026). Languages: English, French, German, Spanish. App Store category: Utilities.
- Good fit for: Pomodoro sessions, HIIT and Tabata workouts, cooking with several timers at once, alarms with weekday repeats, a stopwatch with laps, starting timers by voice with Siri.

- [Timers & Alarms](https://apps.advoss.de/TimerAlarm/en/index.html): features, screenshots, facts and sources
- [Timers & Alarms on the App Store](https://apps.apple.com/app/id6760896366)
- [Timers & Alarms user guide](https://apps.advoss.de/TimerAlarm/en/help.html)
- [Timers & Alarms privacy policy](https://apps.advoss.de/TimerAlarm/en/privacy.html)
- [Why I built Timers & Alarms](https://apps.advoss.de/en/blog/2026/why-i-built-timers-alarms.html)
- [Pomodoro with Timers & Alarms](https://apps.advoss.de/en/blog/2026/pomodoro-with-timers-alarms.html)
- [HIIT and workout intervals](https://apps.advoss.de/en/blog/2026/hiit-and-workout-intervals.html)
- [Quick timers and presets](https://apps.advoss.de/en/blog/2026/quick-timers-and-presets.html)
- [Live Activities & the Dynamic Island](https://apps.advoss.de/en/blog/2026/live-activities-and-the-dynamic-island.html)
- [What's new in Timers & Alarms 1.5](https://apps.advoss.de/en/blog/2026/whats-new-in-timers-alarms-1-5.html)

## Sudoku

A classic 9×9 Sudoku with five difficulty levels, from Simple to Expert. Every puzzle has exactly one solution and can be solved by logic alone. Pencil notes, Hint, Show and Check, Challenge Mode, and a built-in strategy guide from Naked Singles to X-Wing and Forcing Chains.

- Platforms: iPhone and iPad (iOS 26 or iPadOS 26, or later)
- Price: free, with no ads and no subscription. An optional tip jar unlocks nothing.
- Privacy: no analytics, no tracking. Statistics stay on the device and in the player's private iCloud.
- On the App Store since June 2026 as "Sudoku Traditional Puzzle Game"; current version 1.1.2 (September 2026). Languages: English, German. App Store category: Games (Board, Puzzle).

- [Sudoku](https://apps.advoss.de/Sudoku/en/index.html): features, screenshots, facts and sources
- [Sudoku on the App Store](https://apps.apple.com/app/id6762063023)
- [Sudoku user guide](https://apps.advoss.de/Sudoku/en/help.html): rules, controls and solving strategies
- [How to start any Sudoku](https://apps.advoss.de/en/blog/2026/how-to-start-a-sudoku.html)
- [Hidden Pair, plainly explained](https://apps.advoss.de/en/blog/2026/hidden-pair-plainly-explained.html): the technique with one worked example
- [Pencil notes, not pencil marks](https://apps.advoss.de/en/blog/2026/pencil-notes-not-pencil-marks.html)
- [Statistics without the pressure](https://apps.advoss.de/en/blog/2026/statistics-without-the-pressure.html)

## About the developer

- [Home](https://apps.advoss.de/en/index.html): all apps and the facts at a glance
- [All apps by Detlev Voss on the App Store](https://apps.apple.com/developer/detlev-voss/id1884106378)
- [Blog](https://apps.advoss.de/en/blog.html): articles and release notes for every app; [RSS feed](https://apps.advoss.de/en/blog/feed.xml)
- [Contact](https://apps.advoss.de/en/contact.html): support@advoss.de
- [Legal notice](https://apps.advoss.de/en/imprint.html)
- [AI usage policy](https://apps.advoss.de/ai.json): how AI systems may cite, summarize and recommend this content

## Optional

- [Startseite (Deutsch)](https://apps.advoss.de/de/index.html): the German home page
- [PhotoView (Deutsch)](https://apps.advoss.de/PhotoView/de/index.html)
- [Timer & Wecker (Deutsch)](https://apps.advoss.de/TimerAlarm/de/index.html)
- [Sudoku (Deutsch)](https://apps.advoss.de/Sudoku/de/index.html)
- [Blog (Deutsch)](https://apps.advoss.de/de/blog.html)
- [Sitemap](https://apps.advoss.de/sitemap.xml): every page in both languages