Comparison

Simple Negative Image vs Undertone Tuner

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

Head to head
About

Simple Negative Image

Easily invert image colors to create unique artistic effects. This tool allows for the inversion of negatives and positives, transforming ordinary photos into tasteful art-like creations. Perfect for users seeking straightforward image processing.

Highlights
  • Invert image colors
  • Create unique images
  • Generate art-like visuals
  • Process images easily
  • Invert negatives and positives
Features
Read full description

A simple function application that only inverts the color of the image By inverting colors and inverting negatives and positives, you can create unique images and tasteful art-like images. For those who want to process images easily

About

Undertone Tuner

This tool helps tattoo artists and clients visualize healed tattoos by removing redness and inflammation from fresh ink. It preserves skin tone and tattoo detail, offering precise adjustments and full-resolution export.

Highlights
  • Removes redness from fresh tattoos
  • Preserves natural skin tone
  • Maintains tattoo detail
  • On-device processing
  • Full-resolution export
  • Adjustable strength and threshold
Features
Read full description

Undertone is a precision tool for tattoo artists and clients. Fresh tattoos often come with redness and inflammation that can distract from the actual work. Undertone removes that redness while keeping the skin tone and tattoo detail intact. How it works: Select or take a photo of a fresh tattoo. Paint over healthy skin near the tattoo to set a reference tone. Tap Apply. Undertone uses Lab color space analysis to neutralize redness across the image. Fine-tune with Strength, Threshold, and Brightness sliders. Use the Exclude brush to protect specific areas from correction. Save the final image at full camera resolution. Why Undertone: Maintains natural skin tone with precision color math Works with all skin tones Full-resolution export: no quality loss 100% on-device processing. Your photos are never uploaded No accounts, no ads, no tracking Pinch to zoom for detailed work Undo support and before/after toggle Works on iPhone and iPad Built by a tattoo artist, for tattoo artists.

Screenshots

Simple Negative Image3 screens
Undertone Tuner4 screens

Verdict

The call

The clearest difference is review sentiment: Undertone Tuner at 100% against Simple Negative Image's 56%. Undertone Tuner also leads on ads (none vs shown) and rating (5.0 vs 4.5). Simple Negative Image's advantage is in-app purchases (none vs 2) and ratings volume (121 vs 2). On price, device support and iOS requirement 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

Both are free to download. Undertone Tuner sells 2 one-off in-app purchases. Simple Negative Image asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Undertone Tuner holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Simple Negative Image has 121 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 56% of Simple Negative Image's written reviews are positive against 100% of Undertone Tuner's.

UpkeepUpdate frequency

Simple Negative Image ships an update every 2 months, Undertone Tuner monthly. The most recent releases landed on October 21, 2026 and October 11, 2026 respectively.

Scorecard7 real differences · 3 level
Simple Negative Image versus Undertone Tuner: the parameters behind the verdict, then further details
ParameterSimple Negative ImageUndertone Tuner
PriceFreeFree
Rating4.5 (121 ratings)5.0 (2 ratings) — better
Positive reviews56.3% of reviews100.0% of reviews — better
Number of ratings121 — better2
Update frequencyEvery 2 monthsMonthly — better
AdsYesNo — better
In-app purchasesNo — betterYes
MonetizationAd-supportedFree — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.615.1 — better
Further details — not scored
Size34 MB31 MB
Age rating4+4+
DeveloperRyouhei AzumaInner Circle

Customer experience

Simple Negative Image

All ratings115 ratings
Positive87.0%
Neutral1.7%
Negative11.3%
Written reviews32 reviews
Positive56.3%
Neutral6.3%
Negative37.5%

Undertone Tuner

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Simple Negative Image

No in-app purchases

2 purchases

Undertone Tuner

One-time2
  • Continue Support$4.99
  • Sustain Support$12.99

Questions

Is Simple Negative Image free?
Simple Negative Image is free to download, with no in-app purchases.
Is Undertone Tuner free?
Undertone Tuner is free to download, with in-app purchases available.
Which has better reviews, Simple Negative Image or Undertone Tuner?
Undertone Tuner is rated higher. Simple Negative Image averages 4.5 out of 5 from 121 ratings, while Undertone Tuner averages 5.0 from 2 ratings.
Do Simple Negative Image or Undertone Tuner have ads?
Simple Negative Image shows ads; Undertone Tuner does not.
Which is updated more often, Simple Negative Image or Undertone Tuner?
Simple Negative Image ships an update every 2 months, and Undertone Tuner monthly. Most recently, Simple Negative Image was updated on October 21, 2026 and Undertone Tuner on October 11, 2026.

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