Comparison

FitBetween vs CastleFit

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

Head to head
About

FitBetween

This app intelligently finds gaps in your calendar to generate AI-powered workouts tailored to your available time. It requires no equipment and fits movement into your existing schedule, making fitness accessible for busy individuals.

Highlights
  • AI workout generation
  • Calendar integration
  • Time-based workouts
  • No equipment needed
  • Privacy-focused
  • Streak tracking
Features
Read full description

The fitness app for people whose calendars actually run their lives. FitBetween reads your Apple Calendar, finds the openings between your meetings, and generates AI workouts sized to fit those exact gaps. No gym. No equipment. No 90-minute commitment. Just movement that fits the time you actually have. HOW IT WORKS - Connect your Apple/ Google Calendar (read-only, stays on your device) - See your day as openings - 15 minutes here, 45 there - Tap one. Pick a duration. Pick your space. Get an AI-generated workout instantly - Move. Track your streak. Repeat tomorrow. BUILT FOR PEOPLE WHO DON'T HAVE TIME This was built for the founder, the parent, the working person whose Sundays show "12 hours of social media use" and whose calendar shows three free hours they didn't notice. The lie isn't that you're too busy. The lie is that exercise has to be a separate thing you carve out time for. It doesn't. WHAT MAKES IT DIFFERENT - Reads your real calendar — not a generic "schedule a workout" reminder - AI workouts that actually fit your time, not generic 30-min sessions - Three space modes (Small, Medium, Open) so the workout matches where you are - Reminders 5 minutes before each opening - Streak tracking with a 24-hour grace window for the inevitable bad days - Privacy first: calendar data never leaves your phone NOT YOUR USUAL FITNESS APP No social feed. No leaderboard. No body comparisons. No subscription. No ads. Just you, your calendar, and the time you didn't know you had. Made by an indie developer who got tired of fitness apps that didn't fit a real life. -Deston, founder Questions or feedback: hello@fitbetween.app

About

CastleFit

This app offers guided stretching and mobility sessions to relieve pain, improve flexibility, and aid recovery. It provides routines for various needs, from injury recovery to pre-training warm-ups, all accessible at home.

Highlights
  • Guided stretch and mobility sessions
  • Targeted relief for specific body parts
  • HD instructional videos
  • Sessions organized by age, ability, and goals
  • Active and passive stretching routines
  • Device lineup browsing and purchasing
Features
Read full description

Relieve pain. Improve flexibility. Recover faster. Castle Fit brings the full CastleFlexx experience to your phone — guided stretch and mobility sessions built around the device that helps treat the root causes of lower back pain, plantar fasciitis, tight calves, hamstring tightness, and limited mobility. Whether you are recovering from an injury, loosening up before training, or building a daily movement habit, Castle Fit gives you a clear, follow-along routine you can do at home. WHAT YOU GET ◆ Dozens of instructional HD videos and relaxing flows ◆ Sessions organized by your age, ability, and goals ◆ Guided programs from leading trainers and therapists ◆ Active and passive stretching routines for full-body mobility ◆ Targeted relief for calves, hamstrings, hips, lower back, and feet SHOP THE FULL RANGE ▸ Browse the complete CastleFlexx device lineup and accessories ▸ Save your favorites to a wishlist ▸ Fast, secure checkout ▸ Track your orders from purchase to delivery ▸ Get updates on new arrivals and restocks TRUSTED BY EXPERTS AND ATHLETES CastleFlexx is recommended by clinicians and chiropractors and used by professional athletes as part of their recovery. The device pairs stretching with core strengthening for a balanced, controlled experience. BUILT FOR YOUR ROUTINE Follow along at your own pace, choose sessions that match how your body feels today, and come back to the flows that work best for you. Everything is designed to keep you moving, mobile, and pain-free. Download Castle Fit and start moving better today.

Screenshots

FitBetween4 screens
CastleFit4 screens

Verdict

The call

The clearest difference is rating: FitBetween at 5.0 against CastleFit's 2.0. FitBetween also leads on update cadence (every 2 days vs every 2 weeks). On price, ratings volume, ads and in-app purchases 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.

ReceptionRating · Positive reviews · Number of ratings

FitBetween holds the better App Store score, 5.0 against 2.0. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

UpkeepUpdate frequency

FitBetween ships an update every 2 days, CastleFit every 2 weeks. Both last shipped on November 5, 2026.

Scorecard2 real differences · 7 level
FitBetween versus CastleFit: the parameters behind the verdict, then further details
ParameterFitBetweenCastleFit
PriceFreeFree
Rating5.0 (1 ratings) — better2.0 (2 ratings)
Number of ratings12 — better
Update frequencyEvery 2 days — betterEvery 2 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS15.115.1
Further details — not scored
Size37 MB45 MB
Age rating12+4+
DeveloperDeston EvansCastle Flexx

Customer experience

FitBetween

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

CastleFit

All ratings2 ratings
Positive50.0%
Neutral50.0%
Negative0.0%

In-app purchases

None

FitBetween

No in-app purchases

None

CastleFit

No in-app purchases

Questions

Is FitBetween free?
FitBetween is free to download, with no in-app purchases.
Is CastleFit free?
CastleFit is free to download, with no in-app purchases.
Which has better reviews, FitBetween or CastleFit?
FitBetween is rated higher. FitBetween averages 5.0 out of 5 from 1 ratings, while CastleFit averages 2.0 from 2 ratings.
Do FitBetween or CastleFit have ads?
Neither FitBetween nor CastleFit shows ads.
Which is updated more often, FitBetween or CastleFit?
FitBetween ships an update every 2 days, and CastleFit every 2 weeks. Most recently, FitBetween was updated on November 5, 2026 and CastleFit on November 5, 2026.

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