Angel & Devil Series

Fasting Island

Should you keep going, or break the fast? With angel and devil on your shoulders.

A fasting companion app with a comical angel-and-devil exchange on each shoulder. Simple timer + six body-state stages explained + unlimited on-device history. Fully free, no in-app purchases — just one quiet banner ad.

2 languages Fully free, no IAP Unlimited history

Angel & Devil Series

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😈
🪽
😈

Should you keep going, or break the fast? With angel and devil on your shoulders.

Supported OS
iOS 15.0+ / Android 10+
Version
1.0.0
Category
Health & Fitness
Price
Fully free (with banner ad)

Screenshots

In the app

Fasting Island - Timer
Timer
Fasting Island - Body changes
Body changes
Fasting Island - Plan select
Plan select
Fasting Island - History & stats
History & stats
Fasting Island - Character flip
Character flip

Features

Key features

A simple timer

Start, end, that's it. Track your fast in just two taps.

🪽😈

Angel & devil companions

On each shoulder, a kind voice and a devilish whisper bicker through the hours. 80+10 lines so it never gets old.

🌿

Six body-state stages explained

Digestion → glycogen depletion → fat burning → ketosis → autophagy → deep repair — each stage explains what is happening inside, with peer-reviewed PubMed papers (de Cabo 2019 / Longo 2014 / Anton 2018) cited as sources in the in-app "Learn" tab.

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Unlimited history

All sessions, kept forever, on your device. A 7-day bar chart shows your streak.

🎯

Three plans

Pick the pace that fits you: 12:12 / 14:10 / 16:8.

🎉

Goal celebrations

Reach a milestone and the angel celebrates with you — gentle motivation to keep going.

Fully offline
On-device data
Dark mode
EN/JP

Our Promise

Our pledge

Fully free

No subscriptions, no one-time purchases — there are no in-app purchases of any kind.

Quiet ads

A single static banner only, never on the timer screen.

Backed by research

The in-app "Learn" tab cites peer-reviewed PubMed papers (de Cabo 2019 / Longo 2014 / Anton 2018) as sources.

On-device data

Health data stays on your device. We never send it to third parties.

FAQ

Frequently asked

How many sessions can history hold?

Unlimited. Everything stays on your device, kept indefinitely.

Can I migrate history to a new device?

Not in v1.0. iCloud / Google Drive backup is planned for v1.2.

Are there any in-app purchases?

No. The app is fully free, with no subscriptions and no one-time purchases. A single banner ad (Google AdMob) is shown at the bottom of the app, but never on the timer screen.

What if I feel unwell?

Stop fasting immediately, take fluids, salt, and a light snack. If symptoms persist, see a healthcare provider. This app is not medical advice.

Notifications aren't coming through

iOS: Settings → Notifications → app name → enable. Android: App info → Notifications.

Get started today

Fast at your own pace, with a companion on each shoulder.

Share link

Share this URL for direct access to the App Store download page.

rtinformationsystem@gmail.com