# frekvens > Frequency shifter and stereo delay audio effect with advanced modulation. (iPhone/iPad app by Erik Sigth.) - Source: https://appshunter.io/ios/app/frekvens/id1062305416 (this page in markdown: same URL + `.md`) - Developer: [Erik Sigth](https://appshunter.io/developer/385275335) - Category: Music - Price: $2.99 - Rating: 4.80/5 from 21 App Store ratings · 17 written reviews indexed - Age rating: 4+ - Requires: iOS 11.0 · 3 MB - Languages: American English - Released: 2016-02-20 - Data updated: 2026-08-19 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/frekvens/id1062305416/reviews.md ## What is frekvens? Frekvens is a frequency shifter and delay effect. Unlike a pitch shifter all frequencies are shifted linearly and then fed back into itself using the stereo delay unit. The frequency shifting is achieved with single sideband modulation using a hilbert transform and an infinite impulse response filter for fast computations. Frekvens also comes with a high and low pass filter and a lfo for modulating the delay play head. - frequency shifter - high, low pass filter - stereo delay - core midi cc input - audiobus - inter app audio - audio unit extension - save, load ## Key features - Frequency shifter - Stereo delay - High and low pass filter - LFO for delay modulation - Core MIDI CC input - Audiobus and Inter-App Audio support - Audio Unit extension ## Chart rankings - #187 in Top Paid · Music (US App Store) ## Recent user reviews (10 of 17) All indexed reviews: https://appshunter.io/ios/app/frekvens/id1062305416/reviews.md ### 5/5 — Working after a fix made by the author *2021-01-25* Working fine. A nice serious toy who will titillate the ears. Impatient to try more « seriously ». Thanks for Freqvens and Tardigrain top! ### 5/5 — Inexpensive but not cheap *2019-10-13* Put off getting this dev’s apps because they were inexpensive & expected them to cheap quality. Don’t waste time like I did. Get this app, or all of his apps. Read the reviews and trust the experiences. FREAK & NILS are 2 mandatory iOS audio production apps, regardless of genre of style; there is more use for what these do then what is described by the dev or what you should reasonably expect. It’s apps like these, priced to keep you creating competitively, that help the iOS platform offer equitable opportunities for everyone to have the tools to produce great music without worrying about your budget. ### 1/5 — Superb idea, but, unfortunately, absolutely no Accessibility For those relying on Voice-Over! *2019-09-12* Whilst this is a brilliant app, it is utterly impossible to use for anybody requiring voice-over access! Not one of the controls are Accessible, or conform to Apple's Accessibility guidelines, making the app for them totally unusable! A tremendous pity, And the reason I've marked it one sta, rather than the five otherwise it would have received. Many blind and severely visually impaired musicians, Sound designers, etc. use iOS, because of its in-built Voice-Over Accessibility; unfortunately, none of them Will be able to use what otherwise is a superb app! Should this shortcoming be fixed, I would have no hesitation in re-rating this five stars. ### 5/5 — Party over here... *2018-11-19* Ahh..freqvens - probably my favorite iOS effector. This thing can do so much to your sound or you can real it back and it will give your audio a nice little sizzle or warble that, every one’s saying just pleases the ear. I’m not going to tell you no collusion because if you offer some extreme parameters to this device STAND BACK or moreover SIT DOWN because if you close your eyes it sounds like an imperial probe is sexting with the black knight and WHAT THE HELL WOULD THEY BE SAYING TO EACH OTHER ?? Buy this app and find out. ### 5/5 — I have the bundle! *2018-11-06* The controls are somewhat cryptic but once you know what they do (as the on-screen hints indicate) you will find these are very cool apps. ### 2/5 — Cool app, ui has issues on iPhone *2018-11-06* UI elements near corners seldom register taps and overlays can sometimes freeze up on iOS 11. ### 5/5 — Amazing, Bold, and Refreshing *2018-03-01* Amazing little FX app. I have used this to artfully mangle vocal samples in many of my projects. Don’t hesitate, click buy now. ### 5/5 — A must have FX app for IOS music making *2017-01-12* What a brilliant little app this is, at version one. Easy to use, and yet super variable. It really puts to shame those developers who don't add AudioBus and Midi. This has both, and is terrific value. What I'd love to see next update is a way to lock and repeat as a loop each of the parameters, individually, plus State Saving under AudioBus and Ableton Link. Nic ### 5/5 — GENIAL ! *2016-08-29* Tout est midifiable avec cet effet...Qui est complètement fou ! En plus d'être IAA, il est aussi AUX, donc vous pouvez en avoir plusieurs... Et ça sonne à mort ! à ce prix là, c'est juste incroyable... Foncez ! ### 3/5 — Good but... *2016-07-12* This is great audio processor, bit it desparately needs inte-app audio. ## Frequently asked questions about frekvens ### What is frekvens? Frekvens is a paid music application that functions as a frequency shifter and stereo delay effect. It allows for advanced audio manipulation using single sideband modulation and an infinite impulse response filter. ### How much does frekvens cost? Frekvens is a paid app, available for $2.99. This one-time purchase grants access to all its features without any additional in-app purchases. ### Does frekvens have ads? No, frekvens does not contain advertisements. As a paid application, it offers an ad-free experience for its users. ### What devices is frekvens compatible with? Frekvens is compatible with iPhone, iPad, and iPod. It is designed for iOS devices and supports various screen sizes and functionalities. ### What is the age rating for frekvens? Frekvens has an age rating of 4+. This indicates it is suitable for users of all ages, with no content restrictions. ### How often is frekvens updated? The latest version of frekvens is 1.3.16, last updated on November 25, 2025. This suggests a consistent update schedule from the developer. ### What audio integration does frekvens support? Frekvens supports Audiobus, Inter-App Audio, and Audio Unit extensions. It also accepts Core MIDI CC input for external control. ### What do users like about frekvens? Users appreciate frekvens for its advanced audio manipulation capabilities and high-quality sound. Its rating of 4.8 stars from 20 ratings indicates strong user satisfaction with its features and performance. ## Version history (last 5 releases) ### 1.3.16 — 2025-11-25 + Fixing graphical issues in seen menus on iOS 26. ### 1.3.15 — 2025-11-18 + Stability fixes. + Fixing issue handling audio events with an incorrect timestamp. ### 1.3.14 — 2024-07-01 +++ Fixing stability issues. ### 1.3.13 — 2021-01-24 +++ Fixing issue with some devices that only process audio in mono. ### 1.3.12 — 2020-08-09 +++ Updating audio engine to improve IAA compatibility with iOS 12.4 and up. ## Apps similar to frekvens | App | Rating | Price | Category | | --- | --- | --- | --- | | [Dedalus - Delay Audio Mangler](https://appshunter.io/ios/app/dedalus-delay-audio-mangler/id953953694) | 4.6 (41) | $5.99 | Music | | [Phosphor 3](https://appshunter.io/ios/app/phosphor-3/id1499115553) | 4.7 (9) | $5.99 | Music | | [Combustor](https://appshunter.io/ios/app/combustor/id6449939349) | 4.7 (19) | Free | Music | | [Ruismaker FM](https://appshunter.io/ios/app/ruismaker-fm/id1143644577) | 5.0 (54) | $4.99 | Music | | [Surreal Machines Crack](https://appshunter.io/ios/app/surreal-machines-crack/id6615060994) | 5.0 (3) | Free | Music | | [RE-1 Tape Machine](https://appshunter.io/ios/app/re-1-tape-machine/id1407764053) | 4.7 (132) | $4.99 | Music | ## More apps by Erik Sigth - [Sinusoid](https://appshunter.io/ios/app/sinusoid/id416624795) - [shapesynth](https://appshunter.io/ios/app/shapesynth/id431097161) - [ström](https://appshunter.io/ios/app/strom/id495549899) - [nils](https://appshunter.io/ios/app/nils/id579955189) - [voice bot](https://appshunter.io/ios/app/voice-bot/id654025530) - [e-l-s-a](https://appshunter.io/ios/app/e-l-s-a/id833671355) All apps by Erik Sigth: https://appshunter.io/developer/385275335 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-19.*