Comparison

M System vs Trace

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

Head to head
About

M System

Features
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Our app is built to help individuals manage their personal schedule and tasks more efficiently, ensuring that they can stay on top of their daily responsibilities and get more done in less time. We take pride in providing our users with a secure and reliable platform to manage their personal tasks, without compromising their privacy or sharing their data with third parties.

About

Trace

Features
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Free to use. The lye calculator and all six quality numbers are free forever โ€” no account, no ads, no network, works fully offline. Trace Pro is an optional one-time purchase. Trace is a cold-process soap calculator with cited chemistry. Every quality bound, every additive limit, every fragrance cap names its source. FREE FOREVER โ€ข 31 oils with SAP values for NaOH (bar soap) and KOH (liquid soap), cross-checked against AOCS official methods and USDA Agricultural Handbook 8 โ€ข Dual-lye blends for cream soap and shaving soap โ€ข Three water expressions that interconvert cleanly: water % of oils, lye concentration %, water:lye ratio โ€ข Superfat / lye-discount slider โ€ข Citric acid auto-offsets the NaOH calculation (0.624 g NaOH per g citric acid, per Lovin' Soap Studio) โ€ข Sodium lactate, ROE and salt brine math with cited ranges โ€ข IFRA Category 9 (rinse-off toilet soap) fragrance caps for 20 common essential oils โ€ข All six soap qualities โ€” hardness, cleansing, conditioning, bubbly lather, creamy lather, longevity โ€” computed from weighted-average fatty-acid composition, each shown with the range its source publishes โ€ข Adjustable lye purity for NaOH (default 99%) and KOH (default 90%) โ€ข Every cited source listed in one Sources screen THE WEDGE Most soap calculators surface "soap qualities" as opaque numbers. Trace shows the same numbers, free โ€” but on every bound, tap to see exactly which named source backs it. Hardness 29โ€“54: per Kevin Dunn, Scientific Soapmaking (Hampden-Sydney College, 2010). Citric acid 0.624ร— extra NaOH: per Lovin' Soap Studio. IFRA Cat 9 fragrance caps: per the IFRA Standards 51st Amendment (2025). TRACE PRO โ€” OPTIONAL, ONE-TIME Try Pro free for 7 days of actual use โ€” days you don't open Trace don't count against it. After that Pro is a single purchase. No subscription, ever. โ€ข Cost per bar โ€” price your oils once and Trace costs every batch: oils, lye and fragrance totalled, then divided by your bar weight. The one thing a free web calculator cannot do, because it never knows what you paid. โ€ข Save & reopen recipes โ€” keep every recipe you calculate โ€ข Multi-batch cure tracker โ€” log every batch from mix to cured: gel check, unmold, zap test, pH test โ€ข Brand-aware oil-supplier presets: Bramble Berry, Soaper's Choice, Bulk Apothecary, Essential Depot, Wholesale Supplies Plus, plus Costco / Trader Joe's / Spectrum generics SOURCES Kevin Dunn (Scientific Soapmaking), AOCS, USDA Handbook 8, Susan Miller Cavitch (The Soapmaker's Companion), Anne L. Watson (Smart Soapmaking), Modern Soapmaking (Kenna Cote), Lovin' Soap Studio (Amanda Gail Aaron), IFRA Standards, Handcrafted Soap & Cosmetic Guild. THE MOON DOG PROMISE โ€ข No subscription. No ads. No account, no login, no signup, no network. โ€ข Works fully offline. No data collection. DISCLAIMER Sodium hydroxide (NaOH) and potassium hydroxide (KOH) are corrosive and can cause serious burns or eye damage. Always follow your supplier's Material Safety Data Sheet (MSDS) and the safety practices recommended by the Handcrafted Soap & Cosmetic Guild (HSCG). Trace cites named sources but does not generate recipes โ€” independent verification against your supplier's specifications is your responsibility. ยฉ 2026 Roman Kopaliani

Screenshots

M System4 screens
Trace4 screens

Verdict

The call

The clearest difference is in-app purchases: M System at none against Trace's 1. M System also leads on iOS requirement (15.0 vs 17.0). On price, update cadence, ads and device support there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Trace sells 1 one-off in-app purchase. M System asks for nothing beyond the download.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly weekly. The most recent releases landed on October 24, 2026 and October 21, 2026 respectively.

Scorecard2 real differences ยท 4 level
M System versus Trace: the parameters behind the verdict, then further details
ParameterM SystemTrace
PriceFreeFree
Update frequencyWeeklyWeekly
AdsNoNo
In-app purchasesNo โ€” betterYes
DevicesiPhone, iPad, iPod โ€” betteriPhone, iPad
Requires iOS15.0 โ€” better17.0
Further details โ€” not scored
Size206 MB1 MB
Age rating4++4
DeveloperVu Pham AnhRoman Kopaliani

In-app purchases

None

M System

No in-app purchases

1 purchases

Trace

One-time1
  • Trace Pro (lifetime)$6.99

Questions

Is M System free?
M System is free to download, with no in-app purchases.
Is Trace free?
Trace is free to download, with in-app purchases available.
Do M System or Trace have ads?
Neither M System nor Trace shows ads.
Which is updated more often, M System or Trace?
M System ships an update weekly, and Trace weekly. Most recently, M System was updated on October 24, 2026 and Trace on October 21, 2026.

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