ViktorSchiller vs Principle Guy
Price, ratings, monetisation and update history for both apps, side by side β with what reviewers say about each.
ViktorSchiller
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THIS IS NOT a MEDICAL APP! PLEASE DON'T USE IT FOR MEDICAL PURPOSE! Measurements with using oximeter for course BASE. The application is able to measure HRV and show ANS parameters and HRV power spectrum chart. There is a quiz for the diagnoses ratio of burnout syndrome. Disclaimer on Medical Advice This mobile application is not designed to and does not provide medical advice, professional diagnosis, opinion, treatment, or services to you or to any other individual. Through this mobile application and links to other websites, Viktor Schiller provides general information for educational purposes only. THE CONTENTS OF THE VIKTORSCHILLER MOBILE APPLICATION, SUCH AS TEXT, GRAPHICS, IMAGES, INFORMATION OBTAINED FROM VIKTOR SCHILLERβS LICENSORS, AND OTHER MATERIAL CONTAINED ON THE VIKTOR SCHILLER MOBILE APPLICATION (βCONTENTβ) ARE FOR INFORMATIONAL PURPOSES ONLY. THE CONTENT IS NOT INTENDED TO BE A SUBSTITUTE FOR PROFESSIONAL MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT. ALWAYS SEEK THE ADVICE OF YOUR PHYSICIAN OR OTHER QUALIFIED HEALTH PROVIDER WITH ANY QUESTIONS YOU MAY HAVE REGARDING A MEDICAL CONDITION. NEVER DISREGARD PROFESSIONAL MEDICAL ADVICE OR DELAY IN SEEKING IT BECAUSE OF SOMETHING YOU HAVE READ ON THE VIKTOR SCHILLER MOBILE APPLICATION! IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY, CALL YOUR DOCTOR IMMEDIATELY. VIKTOR SCHILLER DOES NOT RECOMMEND OR ENDORSE ANY SPECIFIC TESTS, PHYSICIANS, PRODUCTS, PROCEDURES, OPINIONS, OR OTHER INFORMATION THAT MAY BE MENTIONED ON THE MOBILE APPLICATION. MEDICAL INFORMATION CHANGES CONSTANTLY. THEREFORE THE INFORMATION ON THIS MOBILE APPLICATION SHOULD NOT BE CONSIDERED CURRENT, COMPLETE, OR EXHAUSTIVE, NOR SHOULD YOU RELY ON SUCH INFORMATION TO RECOMMEND A COURSE OF TREATMENT FOR YOU OR ANY OTHER INDIVIDUAL. RELIANCE ON ANY INFORMATION PROVIDED ON THIS MOBILE APPLICATION OR ANY LINKED WEBSITE IS SOLELY AT YOUR OWN RISK. Viktor Schiller does not recommend or endorse any specific tests, products, procedures, opinions, or other information that may be provided on the linked websites. The linked websites may contain text, graphics, images, or information that you find offensive (e.g., sexually explicit). Viktor Schiller, its licensors, and its suppliers have no control over and accept no responsibility for such materials. No Doctor-Patient Relationship NO LICENSED MEDICAL PROFESSIONAL/PATIENT RELATIONSHIP IS CREATED BY USING THE CONTENT, WHETHER SUCH CONTENT IS PROVIDED BY OR THROUGH THE USE OF THE SERVICES OR THROUGH ANY OTHER COMMUNICATIONS FROM VIKTOR SCHILLER. Jurisdictional statement Application Viktor Schiller undertakes to make its mobile application available in accordance with national legislation implementing Directive (EU) 2016/2102 of the European Parliament and of the Council.
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.
Screenshots
Verdict
The clearest difference is update cadence: Principle Guy at every 2 days against ViktorSchiller's every 10 months. ViktorSchiller's advantage is iOS requirement (13.0 vs 15.5). On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
ViktorSchiller ships an update every 10 months, Principle Guy every 2 days. The most recent releases landed on October 13, 2026 and October 24, 2026 respectively.
| Parameter | ViktorSchiller | Principle Guy |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 10 months | Every 2 days β better |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPad, iPod β better | iPhone, iPod |
| Requires iOS | 13.0 β better | 15.5 |
| Further details β not scored | ||
| Size | 58 MB | 90 MB |
| Age rating | 4+ | 4+ |
| Developer | Petr Kolman | ERIK GARAJ |
In-app purchases
ViktorSchiller
No in-app purchases
Principle Guy
No in-app purchases
Questions
Is ViktorSchiller free?
Is Principle Guy free?
Do ViktorSchiller or Principle Guy have ads?
Which is updated more often, ViktorSchiller or Principle Guy?
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