No ads. No clutter. Track 16:8, 18:6, OMAD, and custom plans on iPhone and Apple Watch, with estimated fasting phases and clear progress insights.
Fastly is a clean, private fasting timer for 16:8, 18:6, OMAD, and custom schedules—without ads, accounts, or distractions.
Start a fast with one tap, adjust your start or end time when needed, and see your elapsed time, remaining time, and planned finish at a glance. Fastly keeps the experience focused while giving you the tools you need to understand your routine and track your progress.
FOLLOW YOUR FAST
See estimated fasting phases based on your elapsed fasting time, including digestion, fat burning, ketosis, and autophagy. Upcoming phase markers make it easy to see what comes next during your fast.
TRACK YOUR PROGRESS
Review your complete fasting history through clear statistics, charts, and progress insights. Set weight and body fat goals, and optionally connect Apple Health to keep your measurements organized.
STAY ON TRACK EVERYWHERE
Follow your fasting status from your iPhone, Apple Watch, Home Screen widgets, and complications. Smart reminders help you stay aware of fasting goals and eating windows without unnecessary interruptions.
KEY FEATURES
• Real-time fasting timer with elapsed and remaining time
• Planned fasting end time displayed at a glance
• 14:10, 16:8, 18:6, 20:4, OMAD, and custom plans
• Estimated fasting phases for digestion, fat burning, ketosis, and autophagy
• Upcoming fasting phase markers
• Complete fasting history with statistics and charts
• Weight and body fat goals with progress benchmarks
• Apple Health integration for weight and body fat
• Apple Watch app and complications
• Home Screen widgets for quick progress checks
• Smart fasting and eating-window reminders
• Optional private iCloud synchronization
• Dark mode and a clean, focused interface
PRIVATE BY DESIGN
No ads. No third-party analytics. No developer data collection. Your fasting and health information stays on your devices and, when optional synchronization is enabled, in your private iCloud account.
IMPORTANT NOTE
Fasting phases are estimates based on elapsed time and can vary from person to person. Fastly is intended for general wellness and fasting tracking only. It does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before making medical or dietary decisions.
Everything I was looking for in a keto app - if only all apps were this good.
dbc224
This is a simple, free, minimalist appearing app that checked all my boxes for an app that logs a fast, shows you how long you’ve been fasting and how long you have left as well as how long over your target fast you are. It also tells you (accurate) phases of fasting like fat burning and ketosis. It doesn’t seem to automatically log a fast like so many do without you doing it yourself (I often start at different times or skip a day and hate when my phone tells me I fasted when I didn’t). It lets you edit the fast start and end time, which many do not. It gives a clear, easy to understand graph of data to look back on your fasts. There is an option to pay if you like which I happily did mostly because it was optional. Lastly, there is a 2x2 widget which was important to me. It’s missing a few common fasting plans that span multiple days but that’s not something I do often so doesn’t matter too much. Would be neat if it had a way to integrate weight and body fat percentage from Apple Health or even blood ketones from KetoMojo so you could see how they correlate but sometimes less is more. Overall very happy!
Developer Response
Thank you for the incredibly thoughtful review.We’re glad the simplicity, accuracy, and manual control stood out — that’s exactly what we aim for. We appreciate your support and your ideas for future improvements.
Great Fasting Tracker!
captainlizzard
Works well! I actually like it better than different app I downloaded that wants me to pay a subscription fee to use a bunch of features I don’t really need. Fastly’s interface is sleek and easy to figure out. Logging fasts only takes a few seconds. This is great since I use it every day where having to click through multiple things gets old fast. I also love that they added a notes section so you can keep a diary on how each fast went. This is helpful especially for longer fasts as a newcomer; I can keep a record of where I struggle so I know to what to avoid or improve.
Developer Response
Thank you for your kind words! We’re so glad you’re enjoying Fastly’s simple design and that the Notes feature has been helpful. Thanks for your support!
Almost perfect
Smash1891
I literally have 10 fasting apps currently downloaded trying to find the perfect one. I love the format of yours and how easy it is to edit your fasts as far as start and end. My only suggestion would be to add some graphs. I would like to be able to track my weight as well as see all of previous fasts. I want to be able to track how many hours I’ve fasted for the week, month, etc. if you made those changes this would 100 percent be a 5 star and your app would be the one I’m using. For now I will keep looking but still a great basic app for fasting. Would recommend to anyone that is just simply wanting to track fasts and nothing else. It’s a very simple and straight forward app.
Developer Response
Thank you for such a thoughtful and detailed review — and for trying so many fasting apps to find the right fit.I’m really glad you found the app easy to use, especially the flexibility around editing fast start and end times. That simplicity is very intentional.Your suggestions around graphs, weight tracking, and viewing fasting totals (weekly/monthly hours and history) are excellent and already on my roadmap. Those insights would add meaningful value without compromising the app’s lightweight, straightforward nature.I truly appreciate you taking the time to share this feedback and to recommend the app for users who want a simple, no-frills fasting tracker. I hope to earn that 5-star rating in a future update.Thanks again for giving it a try.
Simple and efficient
Amani555
The app is simple but has all the functions I need. It’s clean and aesthetically pleasing, without any distracting ads or constant prompts to spend money (although you can send a tip if you’d like to show support). The developers clearly respond to feedback and strive to improve the app. The Apple Watch complication is my favorite feature: it’s easy to tell what phase of the fast I’m in or how much time I have left in my eating window. In my opinion, this is the best fasting tracker app. I ended up sending a tip to support the development of this app, I like it so much!
• Fixed an issue where medium and large tips didn’t unlock supporter benefits
• Bug fixes and performance improvements
Version 1.3.20
The developer, Collweb LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
Seller
Collweb LLC
Size
9.6 MB
Category
Health & Fitness
Compatibility
Requires iOS 17.6 or later.
iPhone Requires iOS 17.6 or later.
Mac Requires macOS 14.6 or later and a Mac with Apple M1 chip or later.
Apple Vision Requires visionOS 1.3 or later.
Apple Watch Requires watchOS 10.6 or later.
Languages
English and 8 more
English, French, German, Japanese, Korean, Portuguese, Simplified Chinese, Spanish, Traditional Chinese
