Measured Void Sessions
Flow is derived from weight recorded by a consumer Bluetooth scale (not validated against clinical equipment). Calculated metrics and durations are presented clearly — interactively too.
Personal urination and fluid diary
Measure your urine voids. Track your changes — all on your own terms, in your own iPhone, on your own time, privately.
A single measurement or tracking your voids one day is a snapshot — but your results vary with hydration, food consumed, any stress or anxiety, and dozens of other factors. That variation is the story that a single measurement simply cannot account for.
I built FlowZB from my personal journey with exactly this in mind. FlowZB gives you a longitudinal record of your own voiding — measured at home, on your schedule, in your own conditions — so that when you step back from the data you can see a real story.
FlowZB works with a Bluetooth scale as a measuring device. And, your data stays on your mobile device. Not uploaded anywhere, never shared.
The app is designed for people who want to understand their own bodies. It's a private tool that helps you visualise changes at whatever pace you want.
Connect a Bluetooth scale - Bookoo Themis Mini, Decent Scale - and capture volume and flow rate from the weight curve (more compatible scales coming soon).
No scale? Use a measuring jug. Log volume and duration manually — FlowZB still maps your data for you in a diary style view. Catheter output can be logged this way too.
No way to measure? Out and about? Once you've logged enough sessions throughout several days, FlowZB will use your data and help you estimate your voiding volume.
A handful of focused capabilities, built around people conscious about their urination and voiding. Designed to disappear into your routine, not become it.
Flow is derived from weight recorded by a consumer Bluetooth scale (not validated against clinical equipment). Calculated metrics and durations are presented clearly — interactively too.
Log drinks, food consumed (water content), and night-time estimates alongside all your measured voids. Builds a picture of your voidings over time — the context behind the numbers.
Charts that show how your peak flow, voided volume, and frequency change week by week and month by month. Spot gradual changes a single measurement or one-day tracking would never reveal.
All data is stored on your device using Apple's SwiftData. No account required. No server. Your data can be backed up to iCloud, and will then live in your personal iCloud backup. Only you can access it. Your voiding history is yours — completely and permanently.
When you build a personal voiding baseline over 30 logged days. FlowZB will help estimate night-time volume voids. The morning check-in captures what happened overnight — the part most difficult to track for a full picture.
A built-in reference for the terminology used by FlowZB. It is a more in depth look at how the app uses your data.
Capture and your raw data are always free up to 30 sessions. Data trends and other features are Pro — a one-time purchase permanently unlocks everything described below.
Always. No credit card, no trial period.
One-time purchase. Permanently unlocks everything below:
Short walkthroughs covering the key parts of the app.
Most wellness apps collect your data and ask for your trust. FlowZB is built so that trust is never required — there's nothing to leak, nothing to monetise.
All session data, diary entries, and profile information is stored locally using SwiftData. Data stays on your device (and your own iCloud backup if you enable it). Only you have access to it.
There is no FlowZB backend. There is no database with your information. The data will be backed up in your personal iCloud, but that is under your control if you decide to use it.
You don't sign up, log in, or hand over an email address. The app works entirely without identifying you.
FlowZB contains no analytics, no crash reporting that leaves your device, and no third-party SDKs that observe your behaviour.
Read the full Privacy Policy →
The most-asked questions, all in one place. If yours isn't here, the contact card on the right reaches the person who built the app.
Questions, feedback, or just want to know more about the project? Drop a note below — replies usually come within a couple of days.