1. Home
  2. 💪 Health & Fitness
  3. Fast Slow
Fast Slow - Fasting Tracker

Fast Slow - Fasting Tracker

Intermittent 16:8 Free Timer

36 ratings
4 reviews
🔧 Utilities
💪 Health & Fitness
Free
In-App Purchases

Details

  • Released
  • Updated
  • August 22, 2025
  • September 19, 2026

Features

Developer

Zan Cerne
✨Promote your app ✨
Fast Slow - Fasting Tracker screenshot #1 for iPhone
Fast Slow - Fasting Tracker screenshot #2 for iPhone
Fast Slow - Fasting Tracker screenshot #3 for iPhone
Fast Slow - Fasting Tracker screenshot #4 for iPhone
Fast Slow - Fasting Tracker screenshot #5 for iPhone
Fast Slow - Fasting Tracker screenshot #6 for iPhone
Fast Slow - Fasting Tracker screenshot #7 for iPhone
🧾$2.99 - $9.99
In-App Purchase↘︎
⭐4
Reviews↘︎
🔄6+ apps
Alternatives↘︎
🎪1 in live
Events↘︎
❓8 answered
FAQ↘︎
📦~ in 1 week
Updates frequency↘︎
🖼️Get Icon
Icons↘︎

About

Understand your body's metabolic changes during fasting with a visual timeline. This free app guides you through different fasting zones, from digestion to deep ketosis, and offers customizable schedules and smart notifications. It provides stats, streaks, and widgets for easy progress tracking.

✓Fasting timer with visual timeline
✓6 customizable fasting schedules
✓5 distinct fasting zones explained
✓Smart notifications for fasting windows
✓Stats, streaks, and trends tracking
✓Home and Lock Screen widgets
✓Siri Shortcuts integration
Show original description

What's New in Fast Slow

2.3.0

September 19, 2026

Updated for iOS 27. • Fast Slow is ready for iOS 27, including the Siri and Shortcuts actions. • Small fixes under the hood.

More
4

Subscriptions & In-App Purchases

Legacy - Yearly

Legacy - Yearly subscription for Fast Slow.

$12.991 Year
3 Days trial
Price Updates
July 22, 2026→$12.99
December 7, 2025→$12.99
October 26, 2025→$24.99
How to cancel Fast Slow subscription ⁉️

Events

Read more about Seasonal Fasting Reset
Event EndedLive Event

Seasonal Fasting Reset

Start fresh with guided fasting

Sep 7, 2025 — Sep 29, 2025

Read More

See All

User reviews

Most RecentHighest RatedLowest Rated

LOVE

If I could add more stars, I would. I love everything about this app, and HELLO, it’s FREE without ads or pressure to subscribe at some point. I’m grateful for an app like this in times like these.
jwashkaujwashkau

Response from developer

Thank you! I really appreciate it!

Easy fasting app

I found this app when I wanted to start tracking my intermittent fasting journey. I didn’t have to buy a subscription and it was so easy to track my fasting times and adjust them if necessary. It also keeps a history which I find very useful. I love this app I would definitely recommend it!
MiniGirl88MiniGirl88

Response from developer

That's amazing! Thank you so much for the kind words.

Very good

Been using this for 66 days after my old fast app stopped working. I love how nothing cost money and it shows the different zones my body is in during my fast. Overall great! I recommended to others and they now use it also.
drizzles15drizzles15

Response from developer

Thank you so much! As an indie developer, I really appreciate it! I'm glad you find it useful.

Great fasting app

Simple but has everything I need to fast. The little motivational blurb helps me everyday push through.
AprilhytdbjnAprilhytdbjn

Response from developer

Thank you so much! This means a lot. I'm really glad you're enjoying the app.

Developer apps

Tumpkoti
Tumpkoti

by Zan Cerne

💌 Stickers
Free
Ice Breath: Energize & Focus
Ice Breath: Energize & Focus

Breathwork for Energy & Calm

💪 Health & Fitness
Free
Avtobusnik: Prihodi LPP bus
Avtobusnik: Prihodi LPP bus

Časi avtobusov v Ljubljani

🗺️ Navigation

(2)

Free
See developer apps

FAQ

Does Fast Slow have ads?

No, Fast Slow is completely free with no ads. The developer has stated it is ad-free forever, with every feature included without paywalls or trackers.

What fasting schedules does Fast Slow offer?

Fast Slow provides 6 fasting schedules: 12:12, 14:10, 16:8, 18:6, 20:4, and OMAD (one meal a day). Users can pick a schedule and adjust it as needed.

How does Fast Slow explain fasting zones?

Fast Slow walks users through 5 fasting zones: Anabolic (0-4h), Catabolic (4-8h), Fat Burning (8-12h), Ketosis (12-16h), and Deep Ketosis (16h+). Each zone is explained with its scientific basis.

Can I track my progress with Fast Slow?

Yes, Fast Slow offers stats and streaks, including total fasts, average duration, personal records, weekly trends, and a monthly fasting calendar. This helps users monitor their progress and celebrate small wins.

What devices is Fast Slow available on?

Based on the provided data, Fast Slow is currently supported on iPhone. It also features iCloud sync for seamless data across Apple devices.

How often is Fast Slow updated?

The app was last updated on April 26, 2026, indicating ongoing development and support. The latest version is 2.1.2.

Is Fast Slow suitable for beginners?

Yes, Fast Slow is designed for real life and works for both new and experienced fasters. It offers schedules like 12:12, which is suitable for beginners, and guides users through the process.

Can I export my data from Fast Slow?

Yes, Fast Slow allows users to export their fasting history as JSON data. Users also have the option to delete all their data with a single tap, emphasizing data ownership.