Calendar
297 open source Calendar apps
Clock
APK
Presenting a clock app which was totally made in Jetpack Compose! You can use this app’s timer and stopwatch functions, which are linked to workManager. The animation is added to the app to increase engagement. Moreover, the time is shown in a stylish sliding clock manner.But there’s more than that! Also, you can create one time and recurring alarms and edit, enable, and disable them.
F-DroidGitHubIzzyOnDroid
Clock You
APK
Clock You is a clock and alarm app built with Material Design 3 (You). It supports all the common features such as creating, modifying and scheduling alarms as well as having an inbuilt timer, stopwatch and world clock. Clock You shines when it comes to widgets, it includes multiple modern, material you themed clock widgets. It doesn't have any dependencies apart from the Android base and Material design libraries, therefore the app is very lightweight.
F-DroidGitHubIzzyOnDroid
Clock31
APK
Clock 31 is a Clock + Calendar combo widget for Android, inspired by (but not forked from) the cLock widget found in old versions of LineageOS. The widget shows the current time and date, the next alarm (if any), and upcoming events for all your calendars (the colors on the left indicates the calendar to which they belong). Some useful shortcuts are also provided: tapping the clock will bring you to the clock and alarm app, tapping the calendar icon will open the calendar, tapping an event will bring you to the details of that event.
F-DroidGitHubIzzyOnDroid
Cofi - Brew Timer
APK
As a passionate coffee lover and amateur barista, I've always been on the hunt for the perfect cup of coffee. That's why I created the free and open-source coffee brew timer for Android. With this app, you can easily time your coffee brews and achieve the perfect flavor every time. I know how important it is to have complete control over your brew time, and that's exactly what this app provides. Whether you're using a French press, pour-over, or any other brewing method, our app makes it easy to keep track of your brew time and achieve the perfect flavor. Features: - Open-source and free to use - No artificial limits on what you can add to the app - Timer for your coffee brews - Customizable time settings for different brewing methods - Easy-to-use interface with a clean design and the latest material design - Picture-in-picture mode for multitasking - Wear OS app for easy timing on your smartwatch - Absolutely no user tracking or data collection I know how frustrating it can be to settle for a mediocre cup of coffee. That's why I want to help you brew like a pro and enjoy the perfect cup every time. Download Cofi now and start your journey to coffee perfection!
F-DroidGitHub
Compose Stopwatch
APK
Android stopwatch app in the Material You theme, designed for ease of use and best features ► New Stopwatch Settings • Enable Auto Start 3 seconds after app launch with override option • Enable vibration for better tactile sensation • Select action when you tap on the clock ► Circular progress • Displays the progress of the current lap based on the very first one • A dash on the lap progress shows the previous lap ► Change theme, new themes are available • Dynamic theme is only available with android 12+ • Extra Dark theme saves charging for Amoled screen ► Change orientation • Portrait mode has more space for laps • In Landscape mode, time text is larger ► Select an action when you tap on the clock that shows the time • Resume or pause • Resume or add lap • Resume or pause • If you don't want to do this, you can remove the action ► Switching notifications on/off • Stopwatch control in notifications • When switched off, the stopwatch works on ViewModel and DataStore • When enabled, the stopwatch works on LifecycleService and ForegroundService ► Screen Awake mode • Ability to watch the stopwatch without the screen falling asleep
F-DroidGitHubIzzyOnDroid
Concert Diary
APK
Concert Diary is a simple Android app for recording your concerts and festivals as personal diary entries. --- You can: • Store events with date, location, acts and setlists • Add personal notes and ratings for each event • Attach photos and videos from concerts and festivals • Keep an overview of attended events and artists seen • Manage upcoming events and attach ticket PDFs for quick access --- Automatically fetch artist images via the Deezer API (disabled by default; enable in settings) All data is stored locally on the device using Room. The app is available in English and German. Export and import of database supported. --- Known issue: • Occasionally, theme colors display incorrectly. Toggling the theme off and on again fixes it.
F-Droid
Countdate
APK
Countdate lets you know how many days are left to a specific date. Next to the native app, there's also a web version available.Countdate is and will be free to download and use. As it's open source and under a free license, you can even take the code and modify it!Android、iOS: Ready to use native app.Web: Web version of countdate app is also available.Free to Use: As always, this app is free to download and use!Open Source: Since this app is MIT licensed, you can modify it!
GitHubIzzyOnDroid
Countdown Timer
APK
A simple countdown timer.
F-DroidGitHub
Counter
APK
Counter is an app for counting, by clicking + and - you can increase or decrease the number. Counter uses a flip clock design.What can you do with Counter?CountChange CountReset Count
F-DroidGitHubIzzyOnDroid
Cuppa - Tea Timer
APK
Cuppa for Android is finally here! Tired of leaving your tea too long, to become bitter and cold, or drinking it too soon and not appreciating its full potential? Then this utility is for you! To make the app so quick and easy that you'll actually use it, we have built it with simplicity in mind. Just open the app and tap the button for the type of tea you're brewing. That's it. No need to navigate through complicated menus to find a particular tea, or fiddle with settings... unless you want to customize brew times or add your own favorite teas. Once you tap, Cuppa will begin timing the brew and you'll see a teabag appear in the cup and gradually darken as the tea steeps. A countdown timer shows the steep time remaining. You can have up to two separate teas brewing at once, each with its own countdown timer. When the tea is done Cuppa will let you know with a notification -- depending on your device settings, this may be accompanied by a sound and/or vibration. We hope you find Cuppa for your mobile device useful!
F-DroidGitHub
Daily Screen Time
APK
A minimalist Android application to track your daily screen time and regain control over your attention. Features: * Track daily screen time through a permanent notification * Continuous screen time alerts every 5 minutes * No personal data collection * No internet connection required * Open source and ad-free This application: * Does not collect any personal data * Does not require internet connection * Stores data locally only * Automatically erases data each day
F-Droid
Date-a-base
APK
Your Personal Assistant for Every Special Occasion. Are you tired of scrambling for last-minute gifts or missing important birthdays and anniversaries? Date-a-base is the elegant and intuitive Android app designed to bring peace of mind to your busy life. Keep every special moment alive and celebrated, effortlessly. ✨ Why You'll Love Date-a-base: Effortless Organization: Add birthdays, anniversaries, holidays, and any other important date with just a few taps. Keep everything neatly categorized and at your fingertips. Smart Daily Reminders: Wake up knowing what the day holds! Get a precise notification every morning at 6 AM, summarizing all your upcoming events. Never be caught off guard again. Glanceable Home Screen Widget: Your most important dates, right on your home screen. Our sleek widget updates hourly, showing you what's coming up without even opening the app. Intuitive & Beautiful: Enjoy a modern, user-friendly interface that makes managing your dates a joy, not a chore. Quickly filter by event type or search for specific memories. Your Data, Your Control: Easily export all your precious dates for safekeeping or import them back with a simple CSV file, giving you complete control over your memories. Date-a-base is more than just a calendar; it's your dedicated partner in celebrating life's precious moments. Built with the latest Android technology, it's reliable, secure, and a delight to use. Support Independent Development: If you love Date-a-base and wish to support its continued development, please consider a donation. Your generosity helps keep this app free and open-source! Buy me a coffee
F-DroidGitHub
D
Datenspuren 2025
APK
Programm zur Datenspuren Konferenz https://datenspuren.de Funktionen * Tagesüberblick über alle Programmpunkte * Beschreibung von Veranstaltungen lesen * Veranstaltungen in persönlicher Favoritenliste verwalten * Alle Veranstaltungen durchsuchen * Favoritenliste exportieren * Alarm für Veranstaltungen setzen * Veranstaltungen in Kalender eintragen * Link zu Veranstaltungen mit anderen teilen * Programmänderungen einsehen * Veranstaltungen bewerten * Integration mit dem Zengelsystem-Projekt https://engel.datenspuren.de - Online-Tool für Helfer- und Schichtplanung auf großen Events * Integration mit Chaosflix https://github.com/NiciDieNase/chaosflix - Android App für https://media.ccc.de, teile Fahrplan-Favoriten mit Chaosflix und importiere sie als Bookmarks 🔤 Unterstützte Sprachen (Programmtexte ausgenommen) * Dänisch * Deutsch * Englisch * Finnisch * Französisch * Italienisch * Japanisch * Litauisch * Niederländisch * Polnisch * Portugiesisch, Brasilien * Portugiesisch, Portugal * Russisch * Spanisch * Schwedisch * Türkisch 💡 Inhaltliche Fragen zum Programm kann nur das Datenspuren-Team beantworten. Diese App stellt lediglich die Programmpunkte zur Verfügung. 💣 Fehlerberichte sind herzlich willkommen, aber achte darauf, dass du erklärst, wie man den Fehler reproduzieren kann. Der Issue-Tracker findet sich hier: https://github.com/EventFahrplan/EventFahrplan/issues 🏆 Die App basiert auf der EventFahrplan-App https://f-droid.org/packages/info.metadude.android.congress.schedule/ für den Kongress des Chaos Computer Clubs. Der Quellcode der Anwendung ist auf GitHub https://github.com/johnjohndoe/CampFahrplan/tree/datenspuren-2025 zu finden. 🎨 Datenspuren-Design von nek0
F-DroidGitHub
Deadlines
APK
It shows your deadlines and the time left to finish them. The cards go red as time runs down to finish them.
F-DroidGitHub
Decimal Time Clock Widget
APK
Add a decimal clock widget to your homescreen. * Time of day represented in 100 time units, each divided in 100 equal parts. * Date can be represented on both the Gregorian format and Isaac Asimov's World Season Calendar format.
F-DroidGitHub
DeuFeiTage
APK
Find the date of a public holiday for this or another year. * Choose a German state * Choose a year between this year-4 and this year+4 * Every holiday can be touched to show a short description * The next coming holiday is marked in a different background color
F-Droid
D
DiVOC Schedule
APK
Programm App für das Digital Verteiltes Online-Chaos. https://di.c3voc.de Wir spielen gerade ein sehr gefährliches Spiel auf unserem Planeten und jedes Mal, wenn wir sehen, dass es uns und unsere Lebensgrundlage zerstört, drücken wir dennoch immer wieder auf „continue“. In Wirklichkeit wird nur – wenn überhaupt – ein kompletter Reboot helfen, sowohl politisch als auch wirtschaftlich, sozial und auch kulturell. Wir haben nur eine Erde als Hardware und unser Life-Support läuft aus. Dabei ist die Diskussion, ob etwas getan werden muss, ehrlich gesagt auch schon durch. Deshalb muss jetzt endlich darüber geredet werden, was getan werden soll und wie. Und so ist das Motto des DiVOC zu Ostern „Reboot to Respawn“. Funktionen: * Tagesüberblick über alle Programmpunkte (Vorträge und Self-Organized Sessions) * Beschreibung von Veranstaltungen lesen * Veranstaltungen in persönlicher Favoritenliste verwalten * Favoritenliste exportieren * Alarm für Veranstaltungen setzen * Veranstaltungen in Kalender eintragen * Link zu Veranstaltungen mit anderen teilen * Programmänderungen einsehen * Bewertungen und Kommentare für Vorträge und Workshops hinterlassen * Integration mit dem Engelsystem-Projekt https://engelsystem.de - Online-Tool für Helfer- und Schichtplanung auf großen Events * Integration mit Chaosflix https://github.com/NiciDieNase/chaosflix - Android App für https://media.ccc.de, teile Fahrplan-Favoriten mit Chaosflix und importiere sie als Bookmarks 🔤 Unterstützte Sprachen (Programmtexte ausgenommen) * Deutsch * Englisch * Französisch * Italienisch * Japanisch * Niederländisch * Polnisch * Portugiesisch * Russisch * Spanisch * Schwedisch 💡 Inhaltliche Fragen zum Programm kann nur das Content-Team vom DiVOC beantworten. Diese App stellt lediglich das Programm zur Verfügung. 💣 Fehlerberichte sind herzlich willkommen, aber achte darauf, dass du erklärst, wie man den Fehler reproduzieren kann. Bitte nutze den Issue-Tracker: https://github.com/EventFahrplan/EventFahrplan/issues. 🏆 Die App basiert auf der EventFahrplan-App https://play.google.com/store/apps/details?id=info.metadude.android.congress.schedule für den Kongress des Chaos Computer Clubs. Der Quellcode der Anwendung ist auf GitHub https://github.com/johnjohndoe/CampFahrplan/tree/divoc-2021 zu finden. 🎨 DiVOC Design von faab_e: https://twitter.com/faab_e
F-DroidGitHub
Did I Take My Meds?
APK
Did I Take My Meds? helps keep track of when to take medications. It is designed to help prevent a user from skipping doses and/or overdosing. Did I Take My Meds? allows a user save multiple medications with complex schedules. Each medication can trigger an independent reminder notification. Additionally, this application allows a user to record when they take a dose. As a part of a medication routine, this app can help prevent overdoses and skipped doses.
F-DroidGitHub
Doable
APK
At its core Doable is a modern and easy to use Todo app.It features a beautiful design that follows the latest Material 3 guidelines, a simple user interface that allows you to manage your tasks with ease and last but not least a seamless integration with Nextcloud.When you open Doable for the first time you might be mistaken to think that it lacks some features you might've been hoping for like separate lists. But fear not! Doable does indeed support such things! The are just not enabled by default. To enable lists and other amazing features check out the "Extensions" section in Doable's settings!Doable also supports integration with Nextcloud which allows you to backup and synchronize your tasks across multiple devices – or just keep a handy backup of them in case something goes wrong. Simple log in to your Nextcloud account and boom! Your Todos will now be synchronized automatically. (You can also use any other backup server that supports the WebDAV interface.)
IzzyOnDroid
Dynamic Night Light
APK
Adjustable brightness clock display with illuminated bars. Numbers move around to prevent a screen burn-in. Smoth animations. Clock shows in each direction. Maximal display brightness is 50% (can be changed via options - open via long touch). Connect to power supply to keep display on the whole night. Without power connected the display timouts after default time (can be set via option to keep phone display on even when on battery).
F-DroidGitHub
Elements
APK
Chinese zodiac has five elements: wood, fire, earth, metal and water. You can find unlimited number of documents on these. Chinese zodiac has three treasures: jing for the physical body qi for the horizontal world: humans, animals, connections, all kinds of energy: eg. breath and food, communication, etc. shen for a connection with somewhat spiritual Every day has an element that effects our life in many ways, in all three levels. This little app shows which ones. The rest is upon you. You can find yourself a guru/master/consultant who can calculate your own formula based on your birth date and check out how these effects impact you. I take no responsibility if your life goes up or down based on this. Use with attention and responsibility.
F-DroidGitHub
Enthusiast Tea Timer
APK
Effortlessly organize your tea collection, complete with infusion times and brewing instructions tailored to your taste - whether you prefer Gong Fu Cha or Western style. Enjoy handy presets for popular tea varieties. Take tasting notes, and give star ratings to your teas. Best of all, it's free, open-source, and designed with your privacy in mind - no ads, no data collection. Cheers to your perfect cup!
F-DroidGitHub
Etar - OpenSource Calendar
APK
Features: - Month view. - Week, day and agenda view. - Uses Android calendar storage to show all synchronized calendars. - Material Design. - Dark and light theme. - Support offline calendar. - Agenda widget. - Support sharing calendars via ICS and the ability to import/export from SD card. - Multilingual UI. Bugs and feedback: https://github.com/Etar-Group/Etar-Calendar/issues Source code: https://github.com/Etar-Group/Etar-Calendar
F-DroidGitHub
EteSync - Secure Data Sync
APK
Secure, end-to-end encrypted, and privacy respecting sync for your contacts, calendars, and tasks (using Tasks.org and OpenTasks). For notes, please use the EteSync Notes application. In order to use this application you need to have an account with EteSync (paid hosting), or run your own instance (free and open source). Check out https://www.etesync.com/ for more information. Easy to Use =========== EteSync is very easy to use. It seamlessly integrates with Android so you won't even notice you are using it. Security doesn't always have to come at a cost. Secure & Open ============ Thanks to zero-knowledge end-to-end encryption, not even we can see your data. Don't believe us? You shouldn't, just verify yourself, both the client and server are open source. Full History ========= A full history of your data is saved in an encrypted tamper-proof journal which means you can review, replay and revert any changes you have made at any point in time. How does it work? =============== EteSync integrates seamlessly with your existing apps. All you need to do is sign up (or run your own instance), install the app, and enter your password. After that, you will be able to save your contacts, calendar events and tasks to EteSync using your existing Android apps, and EteSync will transparently encrypt your data and update the change journal in the background. More security, same work-flow.
F-DroidGitHub