Comparison

Just Fasting vs Shifting Source

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

Head to head
About

Just Fasting

Features
Read full description

ust Fasting is built to stay out of your way. Open the app and start fasting—no clutter, no noise. Start fasts your way • 16-hour fast — one tap, last meal is now (adjust if you need to). • Custom fast — pick hours (1–72) or longer fasts in days (4+), with no upper limit on days in the picker. • Last meal time defaults to now but you can change it if you finished eating earlier. Stay oriented A large countdown and an arc show how far you’ve come through your fast. When you hit your goal, wrap up with a tap. See your progress Statistics include total fasts, total time fasted, average length, longest fast, current streak, and best streak. The app remembers your last fast length so starting the same routine again is quick.

About

Shifting Source

Features
Read full description

Shifting Source brings intermittent fasting and the ketogenic diet together in one app. Built as the companion to the book The Keto & Intermittent Fasting Lifestyle, it follows the same principle: understand why it works, and the results will follow. FASTING TIMER WITH LIVE ACTIVITY • Choose 16:8, 18:6, 20:4, OMAD or your own custom window • Follow your fast right on the Lock Screen and in the Dynamic Island • See which phase your body is in along the way, explained in plain language • Extended fasting (48 to 72 hours) with a mandatory safety check before you start KETO WITHOUT THE HASSLE • Log meals with net carbs, fat and protein • TDEE calculator that gives you personal calorie and macro targets • Daily overview of your carbs against your goal TRAINING AND HABITS • Five exercises with instructions and an easier version of each • Log your sets and reps in seconds, including past days • Weekly challenges that grow with you, streaks and badges • Guided breathing exercises for calm and focus INSIGHTS • Calendar with fasts, meals, workouts and wellbeing day by day • Weight, resting heart rate, HRV and sleep from Apple Health • Trends for energy, mood and hunger over time LEARN WHY • Guides and research articles in English, Danish and Swedish • Excerpts from the book, open to everyone • All content is built on peer reviewed research YOUR DATA IS YOURS • No account and no login • Everything is stored on your device • Health data is never shared with third parties • Export or delete everything with one tap Shifting Source does not provide medical advice. Talk to your doctor before starting fasting or a ketogenic diet, especially if you are pregnant, breastfeeding or have a medical condition.

Screenshots

Just Fasting3 screens
Shifting Source4 screens

Verdict

The call

The clearest difference is update cadence: Just Fasting at every 2 days against Shifting Source'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

Just Fasting ships an update every 2 days, Shifting Source every 9 days. The most recent releases landed on October 6, 2026 and September 29, 2026 respectively.

Scorecard1 real difference · 5 level
Just Fasting versus Shifting Source: the parameters behind the verdict, then further details
ParameterJust FastingShifting Source
PriceFreeFree
Update frequencyEvery 2 days — betterEvery 9 days
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPad — betteriPhone
Requires iOS26.426.0 — better
Further details — not scored
Size2 MB9 MB
Age rating4+12+
DeveloperMatthew ClarkHejlsvig Consulting AB

In-app purchases

None

Just Fasting

No in-app purchases

None

Shifting Source

No in-app purchases

Questions

Is Just Fasting free?
Just Fasting is free to download, with no in-app purchases.
Is Shifting Source free?
Shifting Source is free to download, with no in-app purchases.
Do Just Fasting or Shifting Source have ads?
Neither Just Fasting nor Shifting Source shows ads.
Which is updated more often, Just Fasting or Shifting Source?
Just Fasting ships an update every 2 days, and Shifting Source every 9 days. Most recently, Just Fasting was updated on October 6, 2026 and Shifting Source on September 29, 2026.

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