Comparison

Vitamin101 vs Four Days

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

Head to head
About

Vitamin101

Access a comprehensive food encyclopedia detailing vitamins, minerals, fats, and carbohydrates. Quickly find nutritional information for a vast array of food products to make informed dietary choices.

Highlights
  • Vitamins and minerals information
  • Fats and carbohydrates data
  • Extensive food product database
  • Search by product name
  • Advanced food category sorting
  • Nutritional content lookup
Features
Read full description

Vitamin101 shows you what's really in your food. Look up the vitamins, minerals and nutrients in almost 1,000 everyday foods, see how much of your daily needs a portion covers, and keep track of what you eat. FIND ANY FOOD • Browse 19 categories, from fruit and vegetables to meat, dairy, snacks, spices and drinks • Search by name across every category • Advanced Compare ranks a category by any nutrient, such as the fruits highest in vitamin C or the lowest-calorie snacks • Reference sheets explain what each vitamin, mineral and nutrient does EVERY NUTRIENT, YOUR PORTION • Calories, carbohydrates, fats, protein, fiber, sugars, 13 vitamins, 11 minerals, fatty acids and more • Set your portion with a slider or a preset such as 1 oz, 1 cup or 1 lb, and every value updates • Charts show where a food's energy comes from • Show energy in kilocalories, kilojoules or both KNOW YOUR DAILY NEEDS • Choose your age, sex and activity level, or pregnancy or lactation • Every nutrient shows its share of your Dietary Reference Intake • Get an estimated daily energy goal, or set your own • "Rich In" highlights each food's strongest nutrients LOG WHAT YOU EAT • Add foods to breakfast, lunch, dinner and snacks • See the day's energy, macros and progress toward every daily target • Look back at earlier days • Send a food or a whole meal to Apple Health SAVE AND COMPARE • Star your favorite foods and jump back to recently viewed ones • Compare up to three foods side by side, nutrient by nutrient ALWAYS WITHIN REACH • Home Screen and Lock Screen widgets show today's intake at a glance • Ask Siri to log a food or look up a nutrient • Find any food with Spotlight search • Touch and hold the app icon for Log Food, Search and Today's Log • Your log, favorites and settings sync across your iPhone and iPad with iCloud • Keyboard shortcuts on iPad BUILT FOR EVERYONE • Large text, VoiceOver and Voice Control support • Light and dark mode • A short tutorial and a built-in guide to get you started Vitamin101 writes to Apple Health only with your permission and never reads your health data. Your log stays in your own iCloud account. Nutrition values and daily targets are for general information and aren't medical advice. Ask a doctor or dietitian about your personal needs.

About

Four Days

This app helps manage food allergies by tracking your diet. It guides you through a rotation diet to avoid repetitive food consumption and prevent new intolerances. Maintain dietary diversity and support gut health.

Highlights
  • Rotation diet tracking
  • Avoid food repetition
  • Prevent new intolerances
  • Enhance nutrient diversity
  • Support gut healing
Features
Read full description

If you have multiple food allergies, one of the best ways to help yourself is to “rotate” your foods, or eat a rotation diet. Four days allow you to keep track of what you are eating to avoid repetition and prevent you from forming new food intolerances What is a rotation diet? A rotation diet is a system of controlling food allergies by eating biologically related foods on the same day and then waiting at least four days before eating them again. Such a diet can help those with food allergies in several ways and may help prevent the development of allergies to new foods. Why rotate your foods? 1. We are biologically designed to rotate foods. Man is meant to eat with the seasons. We are not designed to eat avocado every single day, because nature does not allow for it. In nature (or even 100-150 years ago) we ate what was local and available. 2. Rotation allows for more nutrient diversity. If we eat avocado as our main source of fat every day, we’re missing out on all of the healthy fats in olive oil, coconut, and beef tallow. Different foods come with different nutrients and we need variety for vibrancy! 3. Eating the same foods constantly can cause food intolerances and impede gut healing Any food, if eaten repetitively, can cause food allergies especially if we have gut issues. Why? Like we stated above, our bodies aren’t designed to eat the same thing over and over again. And if we have permeable intestines and are eating avocado daily, our immune system is reacting to the avocado over, and over, and over again. Eventually it becomes too much. Surely, the goal is to heal the gut. However, an important piece of gut healing is to remove inflammation, and stopping new intolerances from forming. Thus, a rotation diet can be an amazing strategy within a gut healing template.

Screenshots

Vitamin1014 screens
Four Days4 screens

Verdict

The call

The clearest difference is rating: Vitamin101 at 4.7 against Four Days's 2.6. Vitamin101 also leads on review sentiment (84% vs 44%) and ratings volume (63 vs 8). Four Days's advantage is chart position (#74 vs unranked) and price ($1.99 vs $2.99). On update cadence, 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

Vitamin101 costs $2.99 and Four Days $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Vitamin101 holds the better App Store score, 4.7 against 2.6. That said, the two scores are not equally well evidenced: Vitamin101 has 63 ratings behind it against 8, so its average is the more settled of the two. Written reviews point the same way: 84% of Vitamin101's written reviews are positive against 44% of Four Days's.

UpkeepUpdate frequency

Vitamin101 ships an update every 3 months, Four Days every 4 months. Both last shipped on October 29, 2026.

Scorecard7 real differences · 4 level
Vitamin101 versus Four Days: the parameters behind the verdict, then further details
ParameterVitamin101Four Days
Price$2.99$1.99 — better
Rating4.7 (63 ratings) — better2.6 (8 ratings)
Positive reviews83.9% of reviews — better44.4% of reviews
Number of ratings63 — better8
Update frequencyEvery 3 months — betterEvery 4 months
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
Best chart rank—#74 — better
DevicesiPhone, iPadiPhone, iPod
Requires iOS18.013.4 — better
Further details — not scored
Size251 MB23 MB
Age rating4+4+
Developermysteryfiles.nlSergio Gutierrez Mota

Customer experience

Vitamin101

All ratings63 ratings
Positive92.1%
Neutral3.2%
Negative4.8%
Written reviews56 reviews
Positive83.9%
Neutral7.1%
Negative8.9%

Four Days

All ratings8 ratings
Positive37.5%
Neutral12.5%
Negative50.0%
Written reviews9 reviews
Positive44.4%
Neutral22.2%
Negative33.3%

Bugs and requests

Vitamin101

Reported bugs

4 issues
  • Takes forever to download
  • Does not work
  • Login screen freezes
  • Incompatible with older devices

Requested features

14 requests
  • Low carb list (least to most carbs)
  • Expand lists
  • Update information
  • Add more superfoods
  • Break down carbs to show grams of sugar
Show 9 more
  • Add caffein and cocoa
  • Add types of fat in different foods
  • Add foods that compliment each other for absorption
  • Add hominy to food list
  • Add plantains to food list
  • Add suggestions for foods to add
  • Expand food section
  • Improve font readability on mobile
  • Increase table size or allow full screen in landscape

Four Days

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Vitamin101

No in-app purchases

None

Four Days

No in-app purchases

Questions

Is Vitamin101 free?
Vitamin101 costs $2.99, with no in-app purchases.
Is Four Days free?
Four Days costs $1.99, with no in-app purchases.
Which has better reviews, Vitamin101 or Four Days?
Vitamin101 is rated higher. Vitamin101 averages 4.7 out of 5 from 63 ratings, while Four Days averages 2.6 from 8 ratings.
Do Vitamin101 or Four Days have ads?
Neither Vitamin101 nor Four Days shows ads.
Which is updated more often, Vitamin101 or Four Days?
Vitamin101 ships an update every 3 months, and Four Days every 4 months. Most recently, Vitamin101 was updated on October 29, 2026 and Four Days on October 29, 2026.

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