Small Android apps that keep your data on your phone.
Calendar Transfer, by stillfold Last updated: 12 September 2026
Your calendar never leaves your phone. The app copies events from one calendar on your device to another calendar on the same device. There is no server, no account to create, and no analytics.
With your permission, it reads the calendars and events already on your phone, through Android’s standard calendar provider. It reads event titles, times, descriptions, locations, reminders, colours and recurrence rules, because those are the things it has to copy.
With your permission, it creates events in the destination calendar you choose, and nowhere else. It does not modify or delete anything in the calendar you are copying from.
If the destination is a synced account, that account’s own software then uploads those events, exactly as it would for an event you typed in by hand. That upload is performed by Android and the account provider, not by this app.
Nothing about your calendar, automatically, ever.
The app requests internet access for one reason: Google Play Billing, which handles the purchase. Purchases are processed by Google Play, and this app never sees your payment details.
There is no analytics library, no crash reporting library, no advertising identifier and no tracking of any kind.
If you choose to send a problem report, it contains a description of the structure of your calendar and nothing of its content: counts of events, timezone names, which recurrence fields are used, duration formats, colour values, your phone model and Android version, and the types of the accounts involved.
It contains no event titles, no descriptions, no locations, no dates and no account names or addresses. The whole report is shown to you before you send it, it is short enough to read in full, and you choose where it goes using your phone’s normal share menu. Nothing is sent unless you do this.
After each copy the app keeps a small record on the phone so the copy can be taken back: the date, the names of the two calendars, how many events it wrote, which rows in the destination they are, and a fingerprint of each row as it was written, so that a row you have since changed is recognised and left alone. The fingerprint is a hash: nothing about the event can be read back out of it. The record holds no event titles, descriptions, locations or times. It lives in the app’s private storage, is never sent anywhere, and is removed with the app.
The app is not directed at children and collects nothing from anyone.
Beyond the record of copies described above, the app stores nothing, and that record is deleted with the app. Events already copied belong to your calendar account and are managed there, not here.
If this policy changes, the date above changes with it, and the previous versions remain in the project’s history.
stillfold.open988@8alias.com, which is also the contact address on the Play Store listing.