Monitor supplement formula changes with dated label history
A free, ad-free period and cycle tracker that keeps all your data on your phone
Stage
Startup
Not given
Founded
2026
Not given
Based in
US
Not given
Pricing model
Freemium
Free
Pricing
Free Locker: up to 24 saved products with no card required. Signal Pro: $29.99/year (or $3.99/month), includes monitoring for up to 10 products checked daily with email alerts for confirmed changes and monthly Stack Brief.
Not given
Key features
Free Locker holds up to 24 supplements with dated labels
Daily monitoring of up to 10 products
Email alerts when formula changes are confirmed
Before You Reorder comparison of saved and current labels
561 product listings from 65 brands
Signal Verified labels read and dated twice independently
Product Ask feature for ingredient and formula questions
Category Ledger for supplement brands
REST API and MCP server for developers
One-tap period logging with editable calendar
Home-screen widgets for iPhone and Android
Period, fertile window and PMS predictions up to 12 months ahead
Daily logging for flow, pain, mood, energy, sleep, discharge, medication and custom symptoms
Cycle insights by phase
Doctor report as PDF and CSV export
Reminders for period, fertile window and pill with discreet text option
App lock using phone's screen lock
Pregnancy mode with due date and week counter
Data encryption on device with one-step deletion
What makes it different
Every number carries a date and source
No paid placement and no brand influence
Independent and founder-led company
Completely free with no ads, everything stays free
Predictions shown as a range with confidence level and irregular cycle mode
Doctor report and CSV export created on your phone
Reminders scheduled entirely on device with discreet text option
FormulaSignal
Marigold