A no-login, no-cloud iOS companion. Enter two people's names and birthdays and Coincide surfaces the arithmetic their two lives happen to share: the day one is exactly twice the other's age, the birthday their numbers mirror, the moment one outpaces the other's own milestones. Nothing is remembered as "you" — run a fresh comparison for any two people, any time, and generate a PDF report when you're done.
Client: Herr Lambert
Platform: iOS · App Store
Data model: on-device only
Status: for design sign-off
Screen Flow
Tap any step to jump the device to that screen — the prototype underneath is fully live, so you can also just tap around it directly, including real date math for whichever birthdays you type in. Every comparison is independent — nothing is remembered as "you."
9:41••••
🕰️
Welcome to Coincide
Find the exact days two people's ages line up. No account. Nothing leaves the phone.
Person 1
Who's the first person in this comparison?
Person 2
Add the second person to compare.
Coincide automatically works out the day Person 1 becomes older than this person was at Person 1's birth — no extra input needed.
Settings
Appearance
Theme
Palette
Language
About Your Data
Nothing is uploaded, ever. Coincide has no login and no account. The two people you enter for a comparison are calculated on this device only, and are never saved to a server or the cloud. A PDF report you generate is saved wherever you choose on your device — Coincide keeps no copy.
Data
Clear current comparison
Edit Comparison
Milestone
What Coincide Finds
🔁
Double / Half AgeThe day one person is exactly twice the other's age.
✕3
Triple AgeSame idea, at a 3:1 ratio.
💯
Combined = 100The day your two ages add up to a round hundred.
🪞
Mirror AgesAges that are each other reversed — 24 & 42, 13 & 31.
📅
Birthday, Same WeekdayThe next birthday that falls on the same weekday you were born.
👪
Older Than They WerePerson 1 outpaces a parent's age at their own birth, or at a milestone logged for that parent.
🔢
Own Age PalindromeTurning an age that reads the same both ways — 33, 44, 55.
💞
Anniversary CoincidencePartners only — round-numbered anniversaries and combined-age landmarks.
Every card is computed live from the two birthdays entered — nothing is precomputed or hardcoded, including in this prototype.