Comparison

Simply Fast vs DietSensor Keto

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

Head to head
About

Simply Fast

This minimalist app helps you achieve time-restricted fasting goals with a simple, intuitive interface. Configure fasting start times and durations, and receive timely notifications for your fasting and eating windows. No account or sign-in is required.

Highlights
  • Simple and easy-to-use design
  • Customizable fasting start times
  • Adjustable fasting durations (12-23 hours)
  • Fasting and eating window notifications
  • No sign-in or account required
  • Privacy-focused, no data collection
Features
Read full description

Simply Fast is a beautifully simple, no-frills companion for time-restricted eating. Rebuilt from the ground up for the latest iPhone and Apple Watch, it keeps the same clean, one-glance design while feeling right at home on today's devices. Set your window, glance at your progress, and get on with your day. [Features] • Clean, distraction-free design for iPhone and Apple Watch. • Set your fasting start time to any half hour of the day. • Choose a fasting duration from 12 to 23 hours. • A live progress bar shows your current fasting or eating window, with the time remaining at a glance. • Apple Watch complications for modern watch faces, so your window is always one look away. • A notification at the start of each fasting and eating window. • Your schedule stays in sync across iPhone and Apple Watch. • No sign-in, no account, no ads, and no pop-ups. • Private by design: the app collects nothing and sends us no information. [Important] You should consult your doctor before starting or changing a fasting schedule. Simply Fast supports time-restricted eating only, not full-day fasting such as 5:2, and it does not track or store a history of your fasts. [Feedback] We would love to hear from you. Please reach us through the app support page (https://www.mpathy.tech/contact-us). If you find Simply Fast useful, please tell a friend and leave a rating on the App Store. Your support keeps the app going.

About

DietSensor Keto

Achieve ketosis and sustainable weight loss with this comprehensive keto diet app. It guides you through understanding nutrition science, managing hormones, and adopting a low-carb lifestyle with personalized meal suggestions and recipes.

Highlights
  • Achieve ketosis within hours
  • Maintain ketosis and weight loss
  • Adopt sustainable low-carb habits
  • Understand nutrition science for keto
  • Visualize glucose/insulin impact
  • Personalized meal suggestions and recipes
  • Food database with barcode and voice control
Read full description

Whether you're new to Keto, or you're tired of using generic diet apps and calorie counters, we're excited to welcome you to the The DietSensor family with our one-of-a-kind Keto App. DietSensor Keto will help you get into ketosis within hours, maintain ketosis and weight loss for as long as it takes, and then adopt low carb eating habits that are sustainable for life, just like the weight you want to achieve! *** OUR OTHER APPS Weight Loss, Intermittent Fasting, Keto, Sports Nutrition, Diabetes, Nash, Oncology, Cardiology, Epilepsy *** With DietSensor you will discover the nutrition science principles required to follow a ketogenic diet allowing permanent weight loss without the risks to your kidneys and heart that accompany it when it is poorly controlled. These principles are sometimes contrary to the beliefs conveyed by the weight loss industry: ● 1. You will learn how to get your metabolism into ketosis, intelligently using your hormones to trigger the release of body fat. You will also learn about the spike in blood sugar after a meal which drives insulin, the fat storage hormone. Yes, even fats cause an increase in insulin. DietSensor will allow you to visualize this increase and help you correct your meals to stay in ketosis. ● 2. DietSensor will help you get into ketosis in less than 24 hours with intermittent fasting, if you are ready to use this powerful weapon that cleanses the body of all damaged cells and fights oxidation. This can only speed up your results while preventing many diseases. ● 3. Drastically limiting calories and exercising more to lose weight have been shown to always fail in the long run. 80% of your progress will therefore come from a slight calorie deficit, without starving yourself. Sport will be optional, but absolutely not mandatory! ● 4. You'll maintain ketosis with keto-friendly foods that suit your habits and lifestyle: no cooking if you like. Unlike light, bland and boring diets, you can eat natural, tasty and nutritious foods that you like such as meat, eggs, avocado, cheese, or chocolate. Not to mention vegetables and certain fruits, too often ruled out during keto by mistake. Just stick to your program's daily net carbs. ● 5. You will get suggestions, menus and recipes to help with your next meal as well as the associated shopping lists if you require them. ● 6. Once your weight has been reached, DietSensor will help you learn with how to stabilize it with a diet in which carbohydrates will gradually regain their place. You will discover a low carbohydrate diet that offers great freedom and is sustainable for life. This will be your last diet! A COMPLETE AND SETTABLE TOOL ● Setting up Calorie, Net Carb, Fat and Protein percentages and macronutrient goals per meal ● Database of more than 1M foods with barcode and voice control, macro tracking ● Glucose/insulin impact curve with each meal ● Smart Keto Meal Generator, Keto Recipes, Keto Menus and Keto Shopping Lists ● Expert Articles on Keto, Intermittent Fasting, and Diet ● Daily tasks, reminders, motivational messages, analytics and chat with our dieticians 7 days a week ● Tracking of steps, physical activities and water HEALTH APP ● Connect the Apple Health app and import your weight and exercise automatically. Export your meals REWARD ● Voted the most innovative App in the world at CES 2016 PRICES & TERMS OF USE To use the application, you will need to subscribe to a PREMIUM package. We offer renewable subscriptions in the app. Payment will be billed to your iTunes Account upon confirmation of purchase or at the end of the trial period if there is one. The subscription will renew automatically unless automatic renewal is stopped at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours of the end of the current period. Renewal will not result in a cost increase. Manage your subscriptions after purchase in your Account Settings https://www.dietsensor.com/legal

Screenshots

Simply Fast3 screens
DietSensor Keto4 screens

Verdict

The call

The clearest difference is price: DietSensor Keto at Free against Simply Fast's $0.99. DietSensor Keto also leads on rating (5.0 vs 4.5) and ratings volume (11 vs 2). Simply Fast's advantage is in-app purchases (none vs 9) and review sentiment (100% vs 75%). On update cadence, 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

DietSensor Keto is free to download; Simply Fast costs $0.99 up front. DietSensor Keto sells 7 in-app purchases, starting at $29.99 per 3 months. Simply Fast asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

DietSensor Keto holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: DietSensor Keto has 11 ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 100% of Simply Fast's written reviews are positive against 75% of DietSensor Keto's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Simply Fast ships an update every 2 months, DietSensor Keto every 3 months. The most recent releases landed on September 22, 2026 and October 7, 2026 respectively.

Scorecard7 real differences · 3 level
Simply Fast versus DietSensor Keto: the parameters behind the verdict, then further details
ParameterSimply FastDietSensor Keto
Price$0.99Free — better
Rating4.5 (2 ratings)5.0 (11 ratings) — better
Positive reviews100.0% of reviews — better75.0% of reviews
Number of ratings211 — better
Update frequencyEvery 2 months — betterEvery 3 months
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFreemium — better
DevicesiPhone, Apple WatchiPhone, iPod
Requires iOS18.013.0 — better
Further details — not scored
Size2 MB397 MB
Age rating4+12+
DeveloperMpathy TechDietSensor, Inc.

Customer experience

Simply Fast

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

DietSensor Keto

All ratings11 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews8 reviews
Positive75.0%
Neutral0.0%
Negative25.0%

In-app purchases

None

Simply Fast

No in-app purchases

7 purchases

DietSensor Keto

Subscriptions7
  • 3 months Premium$29.993 Months
  • 1 year Premium$39.991 Year
  • Premium 1 month$39.991 Month
Show 4 more
  • 1 year Premium2 variants$49.991 Year
  • 1 year Premium7 Days trial$49.991 Year
  • Premium 3 Months$59.993 Months
  • Premium 1 year7 Days trial2 variants$99.991 Year

Questions

Is Simply Fast free?
Simply Fast costs $0.99, with no in-app purchases.
Is DietSensor Keto free?
DietSensor Keto is free to download, with in-app purchases available.
Which has better reviews, Simply Fast or DietSensor Keto?
DietSensor Keto is rated higher. Simply Fast averages 4.5 out of 5 from 2 ratings, while DietSensor Keto averages 5.0 from 11 ratings.
Do Simply Fast or DietSensor Keto have ads?
Neither Simply Fast nor DietSensor Keto shows ads.
Which is updated more often, Simply Fast or DietSensor Keto?
Simply Fast ships an update every 2 months, and DietSensor Keto every 3 months. Most recently, Simply Fast was updated on September 22, 2026 and DietSensor Keto on October 7, 2026.

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