SpectrumView vs Lumen
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SpectrumView
This app provides real-time audio analysis with a dynamic spectrogram and spectrum analyzer. Visualize audible and inaudible frequencies, measure tones, get feedback on speech, identify sounds, and calibrate instruments. Access recordings and snapshots easily.
- Real-time spectrogram and spectrum analyzer
- Configurable sample rate and frequency resolution
- Record, pause, and playback audio files
- Generate snapshots of spectrum data
- Web file transfer
- Tap data cursor for precise frequency and level
- Musical notes or frequency display on tap
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SPECTRUMVIEW Visualise, in real time, the frequencies that you can hear around you and even those you cannot with SpectrumView, your dynamic audio companion for iPhone, iPad, and iPod Touch. SpectrumView provides a high-quality, real-time spectrogram and spectrum analyser display, with a configurable sample rate and frequency resolution. You can use this application to measure the highest tones you can sing, obtain visual feedback of the frequencies in your speech, identify an annoying sound, calibrate musical instruments and all sorts of acoustic analysis. Here's what it can do for you: · Refresh Spectrogram. Allows users to refresh the spectrogram so that it clears the spectrogram that had already been displayed. · Change min and max scale. Allows users to set their own minimum and maximum scale value on the spectrogram and spectrum analyser view, in both linear and log scale. · Set Recording filename. Recording filenames are editable and the suffix can be set to have an incremental value or date/time. · Generate snapshot of the spectrum data from playback and live recordings. [IAP] · Access recordings and snapshots using the "Files" app. All the data can be easily accessible using the "Files" app that is available from iOS 11. · Web File Transfer. Allows you to access your files from another device using a web browser. [IAP] · Logarithmic scale. Allows you to set either linear or logarithmic frequency scales in the Spectrogram and Spectrum Analyser views. [IAP] · Peak hold. Allows you to freeze and hold the peaks of the frequency envelope (three holds in three distinct colours) in Spectrum Analyser mode. [IAP] · Save location. Never forget where a clip was recorded – uses the devices location services. · Auto lock disabled. During playback and recordings auto lock is disabled to prevent the device from automatically locking (if enabled), for uninterrupted recording/playback · Multiple selectable sample rates from 8,000 Hz to 48,000 Hz · High-frequency resolution with configurable signal analysis window lengths or Fast Fourier Transform (FFT) orders. · Sound intensity represented using a colour spectrum scale from -96 dBFS to 0 dBFS. · Frequency Pinch-to-Zoom. Allows you to zoom into the frequency space to look at a specific tone or frequency. [IAP] · Recording and Playback of Audio Files. Provides a fully functional audio recorder that allows you to record, pause and play back files in high-quality, uncompressed, wave format. · Tap Data Cursor. Allows taps on any part of the Spectrogram or Spectrum Analyser display to obtain the exact frequency in Hertz (Hz) and level in decibels (dB) at that point. · Musical Notes or Frequency Display on Tap. Selectable frequency or musical pitch notation to obtain the cent-accurate musical note e.g. A4 (22), when the display is tapped. · Live Spectrogram and Spectrum Analyser Views of Recorded Files. Files recorded can be played back and the Spectrogram and Spectrum Analyser modes can be used to review the audio. · Sharing Recorded Files by Email or iTunes File-sharing. · High Quality Screenshots. · *Improved* Soundcloud support. Audio files can be uploaded to or downloaded from Soundcloud as well as being able to post audio to Facebook. [IAP] · Playback from iTunes library. Files can now be analysed directly form the iTunes library. · *NEW* Import audio from videos in your device library. · Fullscreen mode. Hide the menu at the bottom of the screen to get even more of the screen dedicated to frequency analysis. · Selectable spectrogram colour scales. You can now select one of 7 colour scales for your spectrogram. · Selectable window functions. You can now see the window function options provided. · Apply gain. A maximum of 24dB gain can be applied to make ‘hard to see’ details easier to view. · Open In. Audio files can be directly opened in SpectrumView. View files sent by email directly in SpectrumView.
Lumen
This app offers a personalized online learning experience with 24/7 access to course materials, live classes, and collaborative tools. Monitor your progress, interact with professors and peers, and manage your assignments and schedule all in one place.
- 24/7 online learning access
- Live classes and professor interaction
- Peer collaboration and discussions
- Performance tracking and assessments
- Offline content downloads
- Assignment submission and reminders
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Online learning made just for you – learn at your own pace, 24x7 accessibility, track your performance, interact, and collaborate with peers and professors. Lumen makes your online learning personalised and easy. The app enables customised end-to-end learning – monitor your performance, run assessments, seamless live interactions with professors, take part in polls, surveys, quizzes, collaborate on assignments with your batchmates, set reminders, chat with your friends. Inspired by the unit of light, Lumen denotes the power of e-learning. It is a self-paced learning management system that helps you stay connected with your campus 24x7. Online learning is a smart choice and Lumen empowers you to learn smart. Afterall bright learners need a brighter future! Access content 24x7, at your convenience Content available at one single source Easy downloads, to save and view offline on your device Capture notes, highlight, curate your quick read for later Bookmark and pick up where you left Attend live classes via the app – no other tool needed Interact with professors seamlessly Take live notes and save for later Doubt clarification Participate in live polls and quizzes Peer Engagement & Learning Doubt clarification during the live sessions – support each other Collaborate with your peers on assignments Engage in breakout rooms Instant messaging Participate in Discussions Start a new discussion or participate in one Voice your opinion on interesting topics Leverage this network Interact with Industry experts Your success & course completion made easy Submit assignments on time Recap videos Refer notes / Q&A Quick support and resolution Customised dashboard – be on top of your game Monitor your performance, real time Set reminders and plan your calendar – mark key announcements and deadlines Personalise your learning plan as per your schedule Leader board & loyalty points to keep you going Download Lumen and learn SMART! Happy Learning!!
Screenshots
Verdict
The clearest difference is review sentiment: SpectrumView at 63% against Lumen's 25%. SpectrumView also leads on iOS requirement (9.0 vs 13.0.1). Lumen's advantage is in-app purchases (none vs 7) and update cadence (every 2 weeks vs every 10 months). On price, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. SpectrumView sells 7 one-off in-app purchases. Lumen asks for nothing beyond the download.
SpectrumView ships an update every 10 months, Lumen every 2 weeks. The most recent releases landed on September 21, 2026 and September 23, 2026 respectively.
| Parameter | SpectrumView | Lumen |
|---|---|---|
| Price | Free | Free |
| Rating | 3.1 (74 ratings) — better | — |
| Positive reviews | 63.0% of reviews — better | 25.0% of reviews |
| Number of ratings | 74 — better | — |
| Update frequency | Every 10 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 9.0 — better | 13.0.1 |
| Further details — not scored | ||
| Size | 17 MB | 75 MB |
| Age rating | 4+ | 4+ |
| Developer | Oxford Wave Research Ltd. | UNext Learning Private Limited |
Customer experience
SpectrumView
Lumen
Bugs and requests
SpectrumView
Reported bugs
11 issues- App crashes on startup after updates
- Crashes when attempting to zoom on spectrograms
- Crashes when playing files from iTunes library
- Microphone hijacking error messages
- Pinch-to-zoom and pan features not functioning properly
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- App freezes when backgrounded
- Spectrogram resets when rotating device orientation
- Audio plays through speaker instead of headphones
- Blank screen with no display output
- Incompatibility with older iOS versions
- Requires in-app purchase prompts for all features after iCloud restore
Requested features
13 requests- Logarithmic frequency scale for audio analysis
- Adjustable time scale/window for spectrograms
- Ability to analyze audio from music library/iTunes
- Longer-term averaging for spectrum analyzer
- A-weighting frequency selection
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- Batch delete option for recordings
- Real-time audio input from playing songs
- Metadata storage (timestamp, location) in WAV files
- SPL meter functionality
- 3D display option
- Adjustable color range for spectrogram
- Auto-readout of highest amplitude frequency
- Higher frequency range support (above 20kHz)
Lumen
Not enough reviews yet to summarise bugs or requests.
In-app purchases
SpectrumView
- Enable peak hold$0.99
- Access iTunes and SoundCould$0.99
- Generate data snapshot$0.99
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- Enable Log Scale$1.99
- Disable recording length limit$1.99
- Enable pinch to zoom$1.99
- Enable Web File Transfer$1.99
Lumen
No in-app purchases









