Constanza is a habit-tracking app that opens and works in seconds. No account, nothing synced to any cloud, no ads and no analytics: it does not even declare the internet permission, so it could not connect even if it wanted to. Each habit gets its own colour -from a palette of 21, or a custom one from its own hue/saturation/brightness picker- and its own schedule: every day, several times a day, a number of times a week, specific days of the week, a day of the month, or every N days. Any schedule can carry one or several reminder times. The Today screen groups what is due now, what is due later, and what you have already answered, and you can step back to any past day to see what happened. Answering is one tap: Yes or No, no dialog to open. And when a reminder arrives, you can answer it right from the notification -Yes, No or Snooze- without even unlocking the phone. A day you do not answer does not disappear: at midnight, any slot left unanswered becomes "Missed". Constanza does not hide what you let slip to make you feel better about it; it records it, and that record is what the streak and the compliance number are built from. Progress shows the current streak, the best streak, and the last-30-days compliance percentage for each habit. Reminders survive a phone reboot and a time or timezone change: you do not need to reopen the app to keep them firing. If your phone does not grant the exact-alarm permission by default, Constanza tells you without blocking anything and takes you to the setting; if you would rather not grant it, reminders still arrive, just with a few minutes of slack. Every night, at 23:00 by default, a review notification reminds you what is still open that day -or only when something actually is, if you would rather set it that way. And in Settings you can change how long a snooze lasts, pick the language (following the system, English or Spanish), and export or import all your data as a file, through the system's own file picker: it is yo