Comparison

Principle Guy vs Trejn

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

Head to head
About

Principle Guy

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Methods are many, principles are few. Principle Guy is an app and a community for movement you will enjoy for life. Everyone with a body is an athlete. Whether you start from zero or have trained for years, the training adapts to you. WHAT YOU GET Home and gym workouts. Ready-made templates for strength, cardio, pilates, yoga and mobility, or build your own. Erik's voice in your ear. He guides you through every exercise, counts you down and reminds you of the technique. A ladder for every movement. Master a level and the app moves you up. No guessing. Progress and records. Workout history, personal records and your daily streak. Nutrition. Calories and macros, a food database, recipes with photos, and food from MyFitnessPal and other apps through Apple Health. Journal. Sleep, weight, steps, water and more, also synced from Apple Health. Principle Check-in. A weekly overview of your training, metrics and nutrition. Challenges. Challenge a friend and train together. Community. Chat with people on the same path, and with Erik himself. WHO IS ERIK Master's degree in sports science, European Jiu-Jitsu champion, WFF PRO bodybuilder and head coach at Epix Gym. He combined football, bodybuilding, calisthenics and science into the Fitness Level system. Repeat and enjoy.

About

Trejn

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TREJN je slovenský tréningový denník a plánovač vytvorený pre každého, kto chce mať svoj tréning a progres pod kontrolou. Zapisuj série, opakovania a váhy priamo počas tréningu. Vytvor si vlastný tréningový plán, sleduj osobné rekordy a pozri sa späť na svoju tréningovú históriu. S TREJN môžeš: • zapisovať tréningy, série, opakovania a váhy • vytvárať a upravovať vlastné tréningové plány • sledovať osobné rekordy a výkonnosť • sledovať telesnú hmotnosť a svoj progres • prezerať tréningovú históriu a kalendár • zaznamenávať RPE a RIR v pokročilom režime • importovať existujúcu tréningovú históriu z Hevy • exportovať a obnovovať svoje dáta pomocou zálohy TREJN funguje lokálne a tvoje tréningové dáta zostávajú uložené v tvojom zariadení. Žiadne zbytočnosti. Tvoj tréning. Tvoj progres.

Screenshots

Principle Guy4 screens
Trejn4 screens

Verdict

The call

The clearest difference is update cadence: Principle Guy at every 2 days against Trejn's every 9 days. On price, ads, in-app purchases 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

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Principle Guy ships an update every 2 days, Trejn every 9 days. The most recent releases landed on November 4, 2026 and October 29, 2026 respectively.

Scorecard1 real difference · 5 level
Principle Guy versus Trejn: the parameters behind the verdict, then further details
ParameterPrinciple GuyTrejn
PriceFreeFree
Update frequencyEvery 2 days — betterEvery 9 days
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPodiPhone, iPod
Requires iOS15.515.1 — better
Further details — not scored
Size92 MB35 MB
Age rating4+4+
DeveloperERIK GARAJRoman Janovec

In-app purchases

None

Principle Guy

No in-app purchases

None

Trejn

No in-app purchases

Questions

Is Principle Guy free?
Principle Guy is free to download, with no in-app purchases.
Is Trejn free?
Trejn is free to download, with no in-app purchases.
Do Principle Guy or Trejn have ads?
Neither Principle Guy nor Trejn shows ads.
Which is updated more often, Principle Guy or Trejn?
Principle Guy ships an update every 2 days, and Trejn every 9 days. Most recently, Principle Guy was updated on November 4, 2026 and Trejn on October 29, 2026.

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