Mister Plimsoll
Disk monitoring alert system
Only for Mac
Free · In‑App Purchases
Mac
Mister Plimsoll watches your Mac's drives and warns you before any of them gets too full. Set a percentage threshold for each volume you want to monitor—your startup disk, external SSDs, or Time Machine destinations—and you'll get an alert when usage crosses the threshold. This helps you take action before a volume becomes too full, which can lead to performance or other problems.
You can choose to receive an alert in one or more of the following ways: macOS notification, floating window, email (you pick the address), Pushover push, or webhook to Slack, Discord, IFTTT, or Zapier. Turn on as many or as few as suit you. You can set the maximum number of notifications per day per volume.
A critical-override threshold (off by default) will keep notifying you after the daily cap is reached when volume is genuinely near full capacity. Mister Plimsoll lives in the menu bar (Dock icon optional), collects no analytics, and stores all settings on your Mac.
Because Time Machine snapshots can sometimes fill startup volumes, once the threshold is reached on regular volumes, Mister Plimsoll shows how much storage is occupied by those snapshots. On Time Machine destinations, the app always shows the storage used for regular Time Machine backups.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Previously, unchecking "Show Mister Plimsoll in Dock" sent the Settings window behind other apps. Now, you can check or uncheck that box and the Settings window remains frontmost.
The developer, Glenn Fleishman, 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.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Glenn Fleishman
- Size
- 602.9 KB
- Category
- Utilities
- Compatibility
Requires macOS 14.0 or later.
- Mac
Requires macOS 14.0 or later.
- Mac
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Large Tip $4.99
- Medium Tip $1.99
- Small Tip $0.99
- Copyright
- ©2026 Glenn Fleishman
