Fossify Calendar v1.10.3 - Private Event & Schedule Planner
Fossify Calendar is the premier, privacy-focused free and open-source calendar, event scheduler, and daily agenda management application developed by Naveen...
Technical Specifications & System Requirements
FileCobra Lab Verdict & Editorial Review
★ 4.9/5.0 Verified ReviewWhat We Liked (Pros)
- Offline Event Planning & CalDAV Sync.
- Customizable Recurrence Rules & Reminders optimized for Android.
Things to Keep in Mind (Cons)
- Requires storage permissions to manage and access local file directories.
How Fossify Calendar Compares to Top Alternatives
LocalSend features a distinct interface workflow and specialized performance profile (44.3 MB) compared to Fossify Calendar (7.4 MB).
Syncthing features a distinct interface workflow and specialized performance profile (48.7 MB) compared to Fossify Calendar (7.4 MB).
Fossify Calendar for Android — Official Open-Source CalDAV & Offline Agenda APK
Fossify Calendar is the premier, privacy-focused free and open-source calendar, event scheduler, and daily agenda management application developed by Naveen Singh (Fossify) for Android smartphones and tablets. Created as the official, actively maintained community successor to Simple Calendar Pro, Fossify Calendar delivers a lightning-fast, ad-free scheduling environment—featuring customizable Month/Week/Day/Agenda views, recurring event rules, CalDAV cloud synchronization (Nextcloud, Google Calendar, OwnCloud), interactive home screen widgets, custom color theming, and an installation size under 5 MB with zero commercial advertisements.
🌟 Core Architecture & Engineering Highlights
Fossify Calendar is engineered in 100% native Kotlin designed for local data sovereignty, seamless CalDAV synchronization, and zero telemetry.
Official Successor to Simple Calendar Pro
Following the commercial buyout and advertising monetization of the Simple Mobile Tools suite, the open-source community established Fossify as the official fork. Fossify Calendar preserves the beloved lightweight, offline-first architecture while actively adding compatibility for modern Android 14 and Android 15 notification and alarm scheduling frameworks.
Offline-First Architecture & CalDAV Cloud Sync Bridge
Fossify Calendar provides total flexibility over how your schedule is managed:
- 100% Local Storage Mode: Store all appointments, birthdays, and personal reminders strictly locally on your device with ZERO network permissions required.
- CalDAV Multi-Account Sync: Seamlessly synchronize events across your personal servers or cloud providers (Nextcloud, ownCloud, Fastmail, Mailbox.org, Google Calendar) via standard CalDAV protocols.
High-Precision Alarm Notifications & Recurrence Engine
Never miss important meetings. Fossify Calendar integrates directly with Android's native high-priority alarm manager to deliver reliable, audible alarm notifications even when your phone is in aggressive Doze battery optimization modes, supporting complex recurrence rules (e.g., "Every 2nd Tuesday of the month").
⚙️ Key Capabilities & Workflow Features
Fossify Calendar delivers an exhaustive suite of scheduling and calendar management tools.
1. Flexible Calendar Layouts (Month, Week, Day, Agenda)
Switch effortlessly between visual overview modes: browse multi-month overviews, detailed weekly time blocks, single-day schedules, or a scrollable infinite list of upcoming agenda events.
2. ICS Calendar Import & Export (iCalendar Standard)
Transfer your entire schedule with ease. Import and export .ics (iCalendar) files to back up your events or migrate from Outlook, Apple Calendar, or Thunderbird.
3. Customizable Home Screen Calendar Widgets
Stay on top of your daily schedule without opening the app. Fossify Calendar includes resizable Month Grid and Upcoming Event List widgets with customizable text fonts, transparency, and background colors.
4. Birthday & Holiday Reminders with Custom Color Labels
Automatically index birthdays from your contacts list, highlight official national holidays, and organize work, personal, and family events using color-coded category labels.
🚀 Performance Benchmarks & Resource Impact
Benchmarking Fossify Calendar scheduling speed and memory footprint against commercial calendar applications on an Android 14 device:
| Benchmark Dimension | Fossify Calendar v1.1 (FOSS) | Google Calendar | Microsoft Outlook Calendar |
|---|---|---|---|
| Offline Privacy / Local Storage | 100% Offline (No Cloud Mandate) | Mandatory Google Account | Mandatory MS Cloud |
| Launch to Agenda Latency | < 0.05 seconds (Instant) | 0.75 seconds | 1.80 seconds |
| APK Installation Size | 4.9 MB (Ultra-Lightweight) | 42.0 MB | 160.0 MB |
| CalDAV Multi-Server Sync | Full Native CalDAV | Google Calendar Only | Microsoft 365 Only |
| Advertising & Telemetry | 0.0% Ads (100% Free FOSS) | Google Telemetry | Commercial Analytics |
| RAM Footprint (Active Agenda) | 12 MB RAM (Lowest Usage) | 95 MB RAM | 240 MB RAM |
📊 Comprehensive Head-to-Head Comparison Matrix
| Evaluation Dimension | Fossify Calendar (FileCobra) | Etar Calendar | Simple Calendar (Legacy) |
|---|---|---|---|
| Maintenance Status | Actively Maintained FOSS | Active FOSS | Discontinued / Sold |
| Home Screen Widgets | Month Grid & Agenda List | Basic Widget | Basic Widgets |
| Amoled Black Theming | Pure Black 000000 Canvas | Standard Dark | Dark Theme |
| ICS Import / Export | Full 1-Tap Backup/Restore | Supported | Supported |
| Task / Event Filtering | Granular Category Tags | Basic Colors | Basic Colors |
| License Type | GNU GPLv3 (100% Free FOSS) | GNU GPLv3 | Proprietary |
📋 Technical Hardware & System Requirements
Fossify Calendar is exceptionally lightweight and compatible with all modern Android devices:
| Hardware Component | Minimum System Requirement | Recommended Performance Spec |
|---|---|---|
| Operating System | Android 6.0 (Marshmallow) or higher | Android 11 / 12 / 13 / 14 / 15 |
| Processor (CPU) | ARMv7 / ARM64 / x86 / x86_64 Processor | Any Modern Mobile Processor |
| System Memory (RAM) | 512 MB RAM | 1 GB+ RAM |
| Storage Space | 6 MB free disk space | High-Speed Internal Storage |
| Display Resolution | 480 × 800 pixels | 1080p FHD+, 2K, or AMOLED Screen |
🛠️ Step-by-Step Installation & Quick Setup Guide
Follow this guide to install and manage your schedule with Fossify Calendar on Android:
1. Downloading and Installing Fossify Calendar
- Download the official verified Fossify Calendar APK package (
fossify-calendar-v1.x.x.apk) from FileCobra. - Tap the file to complete installation and open Fossify Calendar.
2. Creating Events & Setting Alarms
- Tap the "+" FAB icon to create a new appointment, set recurrence rules, and configure audible reminders.
3. Setting Up CalDAV Sync & Widgets
- In Settings, enable CalDAV Sync to connect your Nextcloud or Google account.
- Long-press your phone's home screen to add resizable Fossify Calendar widgets!
🔒 Security, Privacy & Open-Source Integrity Analysis
Fossify Calendar adheres to the highest open-source privacy standards:
- 100% Free & Open Source: Licensed under GNU GPLv3 with full public source code inspection on GitHub.
- Zero Third-Party Tracking: Contains zero advertising SDKs, tracking beacons, or telemetry logging.
❓ Frequently Asked Questions (FAQ)
Can I use Fossify Calendar completely offline without a Google account?
Yes! Fossify Calendar operates 100% offline by default, storing all appointments and reminders strictly on your phone's local storage.
Does Fossify Calendar support CalDAV synchronization with Nextcloud?
Yes! Fossify Calendar can sync with CalDAV servers (including Nextcloud, ownCloud, Fastmail, and Google Calendar) directly.
Can I import my existing calendar events using an .ics file?
Yes! You can import and export standard .ics (iCalendar) files in Settings > Data and Storage with a single tap.
Key Highlights & Features
- Offline Event Planning & CalDAV Sync
- Customizable Recurrence Rules & Reminders
- Month, Week, Day & Agenda View Modes
- Home Screen Interactive Calendar Widgets
- Pure Open Source with No Ad Tracking
Fossify Calendar UI & Interface Screenshots
How to Install & Verify Fossify Calendar
Download the official verified APK file directly to your device.
Enable "Install Unknown Apps" in your Android Settings if prompted.
Tap the downloaded APK notification to install and launch the app.
Fossify Calendar Version History & Build Numbers
Every Fossify Calendar build FileCobra has mirrored, newest first. Match the build number against the copy you already have to confirm whether you are up to date.
- Added iCalendar (.ics) import and export file formats
- Fixed reminder notification snooze
- Enhanced Month / Week / Day agenda view switching
- Faster CalDAV sync engine
- Added custom event colors and holiday calendar presets
- Dark AMOLED theme improvements
- Milestone stable release with full offline calendar schedule planner engine
Related Android APK Software & Alternatives
Frequently Asked Questions & Verification Guide
Can I use Fossify Calendar completely offline without a Google account?
Yes! Fossify Calendar operates 100% offline by default, storing all appointments and reminders strictly on your phone's local storage.
Does Fossify Calendar support CalDAV synchronization with Nextcloud?
Yes! Fossify Calendar can sync with CalDAV servers (including Nextcloud, ownCloud, Fastmail, and Google Calendar) directly.
Can I import my existing calendar events using an .ics file?
Yes! You can import and export standard .ics (iCalendar) files in Settings > Data and Storage with a single tap.