Daybound is an iPhone app I built because I live in the UK on a visa, and the number of days I spend outside the country matters. For settlement you cannot be away more than 180 days in any twelve months. There is a Schengen limit too, and a tax one. I had been keeping all of this in a spreadsheet by hand for four years, one row per day, and I wanted the phone to do the writing for me without taking the spreadsheet away.
What it does
It records the country you sleep in, every night, without you opening it. iOS wakes the app when the phone moves a few hundred metres or settles somewhere, the app works out the country, and the next morning it writes one row to your sheet: the date, the country, and a place for evidence like a flight number.
Then it counts. The interesting part is that every rule counts a day differently. UK settlement only counts whole days outside the country, so the day you leave and the day you come back do not count. Schengen counts any part of a day, so they both do. The tax residence test looks at where you are at midnight. Daybound knows the definition for each rule, and when you open a day it tells you which rules it counts for and why.
The settlement screen goes one step further and tells you the earliest day you can apply, starting from the day your visa started, and starting over if you ever broke the 180-day rule. I learned from it that I had broken it in 2023 without noticing.
Why a spreadsheet
Because these numbers matter for years, and an app is only as durable as the app. Your history is an ordinary Google Sheet in your own Drive. You can open it, send it to a lawyer, back it up, or delete the app; the rows stay. The app creates the sheet itself and can only see the files it created, nothing else in your Drive.
There is a second sheet with every location fix the phone ever took, and you can import your Google Maps Timeline export into it, so the past is yours as well.
Getting it
Daybound is free on the App Store, with no subscription and no account with me. Every screen works with demo data before you sign in with Google, so you can look around first. It is not legal or tax advice; check the rules that apply to you.