PenKeep: Fountain Pen Care
Flush & ink care reminders
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
Manage your fountain pens’ flush cycles and ink drying, with photos. Never pull out a pen that won’t write again. Flush timing by filling system, automatically.
Keep your fountain pens always ready to write.
"I pulled it out and it wouldn't write." "I forgot to flush it for ages." Your pens deserve better — let PenKeep look after their flushing and ink.
■ Flush timing by filling system
Cartridge/converter, piston, eyedropper — each holds a different amount of ink and dries at a different rate. PenKeep estimates the flush timing and gently reminds you as it approaches.
■ Spot the ones drying out
Ink left unused hardens and stops writing. From the last day used, see "Ready" or "May be drying" — a nudge to write with it or flush it.
■ Your collection, in photos
Photograph each pen and the subject is cut out automatically. Your personal collection lined up beautifully.
■ Three-stage flush reminders
Ahead of time (2 weeks, a few days) → on the day → and gently every day after until it's done. Never miss a cleaning.
■ Tips for pen lovers
From flushing technique and ink compatibility to nib handling and iron-gall ink care — 24 tips and a mascot make caring for your collection more fun.
■ Widget support
See pens due for a flush and their status at a glance on your Home Screen.
[Free]
• Register up to 3 pens
• Flush reminders
[Premium]
• Unlimited pens
• Group by pen case or box
• Care log (type, ink, notes)
• No ads
One-time $20 or $1.49/week (no free trial). Subscriptions auto-renew and are billed to your Apple ID unless canceled at least 24 hours before the period ends. Cancel anytime in Settings.
Flush cycles are general guides based on the filling system. Adjust to your ink and how often you write.
■ LINKS
• Support: https://tsuzukit.com/contact/
• Terms of Service: https://tsuzukit.com/legal/terms-of-service.html
• Privacy Policy: https://tsuzukit.com/legal/privacy-policy.html
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Ryo Tsudukihashi, 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 Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Usage Data
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- TsuzuKit
- Size
- 6.3 MB
- Category
- Lifestyle
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
4+
- 4+
- Contains
Advertising
- In-App Purchases
Yes
- Weekly Premium $0.99
- Lifetime Premium $19.99
- Copyright
- © 2026 Ryo Tsuzukihashi