Home About Features Free vs Pro Guides Privacy Support Contact
v1.0 · iOS

Personal urination and fluid diary

Know your flow.

Measure your urine voids. Track your changes — all on your own terms, in your own iPhone, on your own time, privately.

iOS 18.6+ No account On-device only
Why FlowZB exists

Your voiding data belongs to you.

If you're interested in understanding your urination or voiding, you need a tool that tells a story.

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.

The two pictures same person · 6 months
One test N=1
12.3 mL/s
With FlowZB N=178
Snapshot: one number Record: a trajectory
FlowZB session analysis
Three ways to log a session

Use whatever you already have. FlowZB adapts to the hardware in front of you.

01 — Measured

Bluetooth BLE Scale

Available now

Connect a Bluetooth scale - Bookoo Themis Mini, Decent Scale - and capture volume and flow rate from the weight curve (more compatible scales coming soon).

02 — Manual

Jug Volume

Available now

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.

03 — Estimated

Estimates

Available now

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.

What it does

Everything you need. Nothing you don't.

A handful of focused capabilities, built around people conscious about their urination and voiding. Designed to disappear into your routine, not become it.

01

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.

Session analysis screen
02

Personal Diary

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.

FlowZB diary view
03

Trends Over Time

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.

FlowZB trends view
04

Private by Design

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.

05

Night-time Tracking

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.

FlowZB night-time charts
06

Knowledge Map

A built-in reference for the terminology used by FlowZB. It is a more in depth look at how the app uses your data.

FlowZB knowledge map
Free vs Pro

Your data is always yours.

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.

Free £0

Always. No credit card, no trial period.

  • All capture methods — BLE scale, jug volume, estimates
  • Session history — up to 30 sessions
  • Complete diary — drinks, food, notes and voidings in one place
  • Trend charts — core trend charts
  • Knowledge map — definitions and help
  • Raw data export — CSV format
Pro Once

One-time purchase. Permanently unlocks everything below:

  • Everything in Free, plus:
  • Unlimited session history
  • Data trends — what your data is telling you
  • Personal statistics — your baseline and averages, and more
  • Night-time, Frequency and Histograms — Your full context
  • Home metric picker — what you track front and centre
Pro includes the features listed. New capabilities may be offered separately in the future.
How to use FlowZB

Guides & walkthroughs.

Short walkthroughs covering the key parts of the app.

Connecting a BLE scale

Connecting a BLE scale

~40 secHardware setup
Connecting a BLE scale

Using the Diary tab

~40 secDaily logging
Connecting a BLE scale

Reading your trends

~50 secUnderstanding your data
More videos coming soon. In the meantime ask a question.
Your data

Private by design, not by policy.

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.

Stays on your device

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.

No server, no FlowZB cloud

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.

No account required

You don't sign up, log in, or hand over an email address. The app works entirely without identifying you.

No advertising, no tracking

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 →

Help

Common questions.

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.

What do I need to use FlowZB?
An iPhone running iOS 18.6 or later. For measured sessions you'll also need a compatible BLE weight scale (or our bespoke flow sensor when it becomes available). Manual entries and jug modes require no hardware at all.
What is FlowZB?
FlowZB is a personal urine voiding tracker. Think of it as a detailed diary of your voiding routine.
Which BLE scales are compatible?
FlowZB currently recognises the Bookoo Themis Mini and the Decent Scale. Support for additional hardware is ongoing.
Can I export my data?
Yes. FlowZB can export your session history as CSV — voided volume, flow metrics, timestamps, and capture method, which you can use for your own analysis. A PDF summary export is also on the roadmap.
How do I delete my data?
All data lives on your device and is backed up to your personal iCloud so your data is safe if you change phones. Individual sessions and diary entries can be deleted from within the app at any time. Also, there is a dedicated function in the app settings page to safely delete all your data from your device and iCloud.
Get in touch

A direct line to the developer.

Questions, feedback, or just want to know more about the project? Drop a note below — replies usually come within a couple of days.

Message sent. Thank you.
Something went wrong. Please email support@zoneblanche.co.uk directly.