Comparison

Rubo Gems vs Viking Synth

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

Head to head
About

Rubo Gems

Easily create your own music with a vast library of loop combinations. Whether you're a beginner or a professional, this app offers a simple yet powerful way to craft beats and grooves for any musical experience.

Highlights
  • Easy song creation
  • Millions of loop combinations
  • Create beats and grooves
  • Suitable for novices and professionals
  • Intuitive swipe interface
Features
Read full description

Rubo Gems is the world's easiest and most popular song creator! It was formerly called "#remix" and was featured by Rolling Stone Magazine and used by some of the world's top bands. Serj Tankian of 'System of a Down' used it to create three songs on his album, "Harakiri". Try it for yourself and see why it reached #1 in the world. Whether you're a novice mixer or a world class DJ, you can create fantastic music with Rubo Gems. With a few swipes of your finger and a touch of soul you'll be creating powerful beats and grooves in no time. You can get loud and host an EDM Extravaganza, or put on headphones and drift away in your own musical experience. With over 7 trillion loop combinations, there's just no stopping you. Hear that rumble? That's your inner DJ. It's time to free your play! Rubotic created to create

About

Viking Synth

This app emulates a classic monophonic analog synthesizer with advanced DSP technology. It features three variable wave oscillators, dual ladder filters, an LFO, and two modulation busses for versatile sound design. An intuitive interface and extensive preset library make it ideal for creating thick bass and rich lead sounds.

Highlights
  • Three continuously variable wave oscillators
  • Dual ladder filters (Lowpass/Highpass)
  • Multi-wave LFO
  • Two modulation busses
  • Intuitive user interface with expandable controls
  • 228 presets including Bass, Lead, and Synthwave
  • State-of-the-art DSP for authentic sound
Read full description

Viking Synth is an authentic emulation of a classic monophonic analog synthesizer. It has three continuously variable wave oscillators, two ladder filters with a Dual Lowpass or Highpass/Lowpass configuration, a multi-wave LFO, and two modulation busses. Viking Synth uses state of the art DSP technology to accurately reproduce the sound of the hardware. You get a desktop quality plug-in at an iOS friendly price. Viking Synth is an Audio Unit Extension Instrument (AUv3) that works as a plug-in inside host apps. Just open up your favorite host that supports Audio Unit Instruments and select it from the list of available Audio Units. Compatible with GarageBand, Cubasis, Auria, BeatMaker, AudioBus, AUM, Modstep, and more. The user interface of Viking Synth is designed for quick and intuitive control. Knobs and sliders expand during tweaking and are designed so the current value isn't hidden below your finger. The six pages divide the synth into logical sections that can be accessed quickly. The filter display acts as an XY pad for controlling cutoff and resonance. Simply double tap a knob or slider to reset it to its default value. Presets Viking Synth comes with 228 presets in the categories Bass, Bright Lead, Electro Bass, FX, Percussive Lead, Soft Lead, and Synthwave. The synth excels at thick bass and rich lead sounds. The 50 Electro Bass and 50 Synthwave presets were designed by renowned sound designer eXode. Presets work perfectly with GarageBand, Cubasis, and AUM. Oscillators At the heart of Viking are three adjustable wave oscillators. The continuously variable waveform knob gives the oscillators a unique sound that can’t be achieved with the fixed waveforms found in most synths. A noise oscillator provides three types of noise, one specifically modeled after the hardware. Modulation Two modulation busses and an LFO provide flexible modulation capabilities. All of the options hidden deep in menus on the hardware are immediately accessible with one tap. Filters The filters are classic transistor ladder filters modeled meticulously. Two DSP varieties are available allowing for either reduced CPU load or soft clipping plus three additional overdriven modes. The number of poles is adjustable for a wider range of filter sounds. Compare Viking to other synths: – Viking’s oscillators are free running, not sampled, wavetable based, or generated from a zero point – Viking’s oscillators use advanced techniques to avoid aliasing – Viking’s oscillators have instability, which is controllable through the tuning drift control – Viking’s nonlinear filter uses circuit modeling and provides soft clipping

Screenshots

Rubo Gems3 screens
Viking Synth4 screens

Verdict

The call

The clearest difference is price: Rubo Gems at Free against Viking Synth's $3.99. Rubo Gems also leads on update cadence (every 10 days vs every 4 months). Viking Synth's advantage is rating (4.7 vs 4.1) and in-app purchases (none vs 1). On review sentiment, ratings volume, 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

CostPrice · In-app purchases · Ads · Monetization

Rubo Gems is free to download; Viking Synth costs $3.99 up front. Rubo Gems sells 1 one-off in-app purchase. Viking Synth asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Viking Synth holds the better App Store score, 4.7 against 4.1. Both are backed by a comparable volume of ratings — 31 and 41 respectively. Written reviews point the same way: 69% of Rubo Gems's written reviews are positive against 71% of Viking Synth's.

UpkeepUpdate frequency

Rubo Gems ships an update every 10 days, Viking Synth every 4 months. The most recent releases landed on October 22, 2026 and October 20, 2026 respectively.

Scorecard5 real differences · 5 level
Rubo Gems versus Viking Synth: the parameters behind the verdict, then further details
ParameterRubo GemsViking Synth
PriceFree — better$3.99
Rating4.1 (31 ratings)4.7 (41 ratings) — better
Positive reviews69.2% of reviews71.2% of reviews — better
Number of ratings3141 — better
Update frequencyEvery 10 days — betterEvery 4 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.012.0
Further details — not scored
Size234 MB11 MB
Age rating4+4+
DeveloperRubotic, Inc.Blamsoft, Inc.

Customer experience

Rubo Gems

All ratings31 ratings
Positive77.4%
Neutral6.5%
Negative16.1%
Written reviews684 reviews
Positive69.2%
Neutral10.5%
Negative20.3%

Viking Synth

All ratings42 ratings
Positive92.9%
Neutral0.0%
Negative7.1%
Written reviews66 reviews
Positive71.2%
Neutral10.6%
Negative18.2%

User reviews

Rubo Gems

From 31 App Store ratings

What we love

  • 🎶 Awesome music creation
  • 👍 User-friendly interface
  • 💡 Great for beginners
  • 🎨 Lots of creative possibilities

Room to improve

  • 🐛 Crashes and bugs
  • 🔒 Requires internet connection
  • 💰 In-app purchases needed
  • 🔀 Confusing UI changes

Viking Synth

From 41 App Store ratings

What we love

  • 🎶 Great sound quality
  • 💡 Versatile sound options
  • 💰 Excellent value (free)
  • 💻 Lightweight and efficient
  • 🎹 Good for learning synthesis

Room to improve

  • ❓ Preset issues
  • 🔌 Not a standalone app
  • 🐛 Occasional crashes
  • 💾 Settings not saving
  • 🤷‍♂️ Difficult to find/use

Bugs and requests

Rubo Gems

Reported bugs

4 issues
  • App crashes on startup
  • Record button doesn't work
  • Saved songs deleted after update
  • Compatibility issues with newer iOS

Requested features

4 requests
  • Add more sound samples
  • Improve export/sharing options
  • Offline mode support
  • Restore previous app layout

Viking Synth

Reported bugs

6 issues
  • Presets not showing up
  • Presets disappear
  • App not showing in AUv3 menu
  • Settings not saving after iOS 14 update
  • Crashes when opening presets browser
Show 1 more
  • Saved presets not loading

Requested features

5 requests
  • More subtle drive mode
  • Categorized preset browser
  • Polyphony option
  • Dark mode
  • More apps from developer

In-app purchases

1 purchases

Rubo Gems

One-time1
  • Upgrade$1.99
None

Viking Synth

No in-app purchases

Questions

Is Rubo Gems free?
Rubo Gems is free to download, with in-app purchases available.
Is Viking Synth free?
Viking Synth costs $3.99, with no in-app purchases.
Which has better reviews, Rubo Gems or Viking Synth?
Viking Synth is rated higher. Rubo Gems averages 4.1 out of 5 from 31 ratings, while Viking Synth averages 4.7 from 41 ratings.
Do Rubo Gems or Viking Synth have ads?
Neither Rubo Gems nor Viking Synth shows ads.
Which is updated more often, Rubo Gems or Viking Synth?
Rubo Gems ships an update every 10 days, and Viking Synth every 4 months. Most recently, Rubo Gems was updated on October 22, 2026 and Viking Synth on October 20, 2026.

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