Comparison

Glassful vs 4Level

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

Head to head
About

Glassful

Features
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A water tracker you'll actually want to open. Glassful turns your daily water goal into a real glass bottle on your screen. Every drink you log pours in, ripples and settles. Tilt your phone and the water tilts with it. HOW IT WORKS โ€ข Tap once to log a glass and watch the bottle fill. Mis-tapped? Undo in one tap. โ€ข Log any amount with the keypad and quick presets. โ€ข Set your daily goal in liters or fluid ounces. โ€ข Get gentle reminders to drink water through the day. A BOTTLE THAT FEELS REAL โ€ข Real-time 3D glass with reflections and refraction. โ€ข Water that stays level as you move your phone. โ€ข Touch the surface and watch it ripple. PICK YOUR BOTTLE Clear Glass is free. Unlock Frosted Glass, Dark Glass, Crystal and the other bottle types with Premium. WORKS WITH APPLE HEALTH Glassful can save every drink you log to Apple Health, so your water sits alongside the rest of your health data. You choose what to share and can change it anytime in the Health app. PRIVATE BY DEFAULT No account needed. Your logs stay on your iPhone. GLASSFUL PREMIUM Every bottle and your full history. Choose monthly, yearly with a free trial, or a one-time lifetime unlock. Subscriptions renew automatically unless cancelled at least 24 hours before the period ends; manage them in your Apple Account settings. Privacy Policy and Terms of Use: https://keytotech.com/glassful/privacy-policy Glassful is a hydration tracker, not medical advice. If a health condition affects how much you should drink, ask your doctor what goal is right for you.

About

4Level

Features
Read full description

4Level is made for ambitious amateur athletes who already train regularly and want to know: How fit am I really โ€” and am I sticking to what I set out to do? WHAT 4LEVEL IS โ€” AND WHAT IT IS NOT 4Level analyses the workouts you already record. It does not create training plans, workouts or coaching advice and does not replace a coach. You decide how you train; 4Level measures, explains and keeps you honest. YOUR LEVEL, 1 TO 100 One number from three building blocks: โ€ข Fitness โ€” your training load of the last six weeks (CTL) โ€ข Capacity โ€” running VOโ‚‚max (VDOT) or cycling watts per kilo โ€ข Consistency โ€” how regularly you train and, once you set your resolutions, how faithfully you keep them Calculated for every single day back to your first workout, using only what was known on that day. Every value shows whether it was measured or estimated; the whole formula is explained in the app. STICK TO YOUR RESOLUTIONS Set per sport โ€” running, cycling, hiking, swimming, strength โ€” how often and on which days you intend to train, or train as you feel like it. Add weekly, monthly or yearly kilometre targets if you like (not for strength). 4Level shows whether you are ahead or behind right now, a 26-week heatmap, your streak in weeks and your month balance. Flexible by design: ran Monday, Tuesday and Saturday instead of Monday, Wednesday and Friday? The week still counts. Measured retroactively for the last 26 weeks if you want. LOAD, FATIGUE AND FRESHNESS Fitness, fatigue and freshness (CTL, ATL, TSB) show whether you are rested, building or overloaded โ€” judged on the trend of the last days, not on how tired you are right after a session. Race predictions for 5 km to marathon come from your runs of the last 120 days: pace and, if you record it, heart rate. RECOVERY After each session dots fill the gap at the bottom of your level ring; when the ring closes, you are recovered. How long that takes depends on the load and intensity of the session and on your fitness. 4Level also reads resting heart rate, heart rate over the day, HRV and cardio recovery, analyses your history once and adapts the recovery time to how you actually recover โ€” Apple Watch or another device that writes heart rate to Apple Health. A notification when you are recovered is optional. RUNNING, CYCLING AND HIKING Yearly goals with a marker where you should be today, this year against last year and your best year, weekly volume, records, all years at a glance. Plus a searchable list of all your workouts. WORKS WITH THE APPS YOU USE 4Level reads from Apple Health โ€” everything your Apple Watch, Garmin Connect, Strava, Zwift, Wahoo and other apps write there. You choose per sport which app's recording counts; the same session recorded twice counts once, and missing heart rate, climbing or power is filled in from the other recording. PRIVATE BY DESIGN No account, no server, no analytics, no ads. Data is read from Apple Health and stays on your device. PRICING 30 days free with everything included. Afterwards 4Level Pro: a yearly subscription (renews automatically, cancel anytime in your Apple Account settings) or a one-time lifetime licence. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ The level is a training aid, not a medical assessment. Try the demo without any data.

Screenshots

Glassful4 screens
4Level4 screens

Verdict

The call

The clearest difference is iOS requirement: Glassful at 17.0 against 4Level's 26.1. On price, update cadence, ads and in-app purchases there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Glassful sells 3 in-app purchases, starting at $2.99 per month and 4Level sells 2 in-app purchases, starting at $1.99 per year. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Glassful ships an update every 2 weeks, 4Level weekly. Both last shipped on October 29, 2026.

Scorecard1 real difference ยท 5 level
Glassful versus 4Level: the parameters behind the verdict, then further details
ParameterGlassful4Level
PriceFreeFree
Update frequencyEvery 2 weeksWeekly โ€” better
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.0 โ€” better26.1
Further details โ€” not scored
Size19 MB8 MB
Age rating4+4+
DeveloperKeyToTechRobert Poetzsch

In-app purchases

3 purchases

Glassful

Subscriptions2
  • Premium Monthly$2.991 Month
  • Premium Annual3 Days trial$12.991 Year
One-time1
  • Premium Lifetime$24.99
2 purchases

4Level

Subscriptions1
  • 4Level Pro Yearly$1.991 Year
One-time1
  • 4Level Lifetime$8.99

Questions

Is Glassful free?
Glassful is free to download, with in-app purchases available.
Is 4Level free?
4Level is free to download, with in-app purchases available.
Do Glassful or 4Level have ads?
Neither Glassful nor 4Level shows ads.
Which is updated more often, Glassful or 4Level?
Glassful ships an update every 2 weeks, and 4Level weekly. Most recently, Glassful was updated on October 29, 2026 and 4Level on October 29, 2026.

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