Mixpanel, OneSignal, and Crashlytics in one self-hosted stack - Countly is an all-in-one product analytics and engagement platform where every byte of first-party data stays on your server. A Node.js application over MongoDB, it collects through ten battle-tested SDKs spanning iOS, Android, web JavaScript, React Native, Flutter, Unity, and desktop (plus a data write API for anything else), and has powered tens of thousands of mobile, web, and desktop apps since 2012. The analytics core covers sessions, custom events, views, user profiles, and real-time dashboards, with exploration tools built for product managers as much as analysts. What separates Countly from pure analytics tools is acting on the data without third parties: built-in push notifications send automated, transactional, and personalized messages to iOS (APNs), Android (Firebase), and Huawei devices, with the SDK handling token retrieval and permission flows automatically; crash reporting captures symbolicated native crashes on iOS and Android plus JavaScript errors, correlated with the same user and session data. Email reports keep stakeholders updated, and the plugin-based architecture means features load as modules. For GDPR-sensitive products, engagement without piping user data to advertising companies is the entire point. AGPL-licensed server, installable in minutes.

With 21,400 GitHub stars, 500+ contributors, and battle-tested since its 2016 open-source release after powering Facebook's mobile backend infrastructure, Parse Server delivers production-grade Backend-as-a-Service that eliminates months of custom API development. The platform generates REST and GraphQL endpoints automatically from your data schema with class-level permissions and object-level ACLs providing granular access control. Cloud Code enables server-side JavaScript execution for triggers (beforeSave, afterSave, beforeDelete, afterDelete), custom functions, and scheduled jobs — all deployable without restarting the server. Live Queries push realtime data changes to subscribed clients via WebSockets, powering chat applications, collaborative editors, and live dashboards. Push notification support spans APNs for iOS, FCM for Android, and web push for browsers with audience segmentation, scheduling, and delivery analytics. The Parse Dashboard provides a comprehensive admin interface with a data browser featuring configurable info panels, graph visualization, custom canvas builder with draggable elements, AI agent integration via OpenAI, data import/export, and multi-factor authentication. Database flexibility supports MongoDB 6-8 and PostgreSQL 13-18 with PostGIS for geospatial queries. Native SDKs cover JavaScript, iOS (Swift/Objective-C), Android, Flutter/Dart, .NET/Xamarin, Unity, PHP, and Arduino for IoT devices. Deploy via npm, Docker, or the official Express template with automatic schema migration. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

ntfy sends push notifications to your phone or desktop with a single curl command: publish a message to any topic and every subscriber receives it instantly, no signup or API key required. Over 31,000 GitHub stars and 106 releases since 2021 back a server supporting five priority levels mapped to distinct notification sounds and vibration patterns, emoji tags for visual classification, click actions that open URLs when tapped, and up to three action buttons per notification for view, HTTP callback, broadcast, or clipboard copy operations. File attachments push images from surveillance cameras, documents, or any binary payload directly to mobile devices. Subscriptions work through JSON streams, Server-Sent Events, WebSockets, or raw text, with server-side filtering by priority, tags, and message ID. Authentication enforces topic-level access control through Basic Auth, Bearer tokens, or query parameters, with a built-in user and ACL management system. UnifiedPush compatibility lets ntfy serve as a push distributor for Mastodon, Matrix, and other federated services. Web Push via VAPID keys delivers browser notifications without the mobile app. The server ships as a single statically linked Go binary or Docker image supporting amd64, armv7, and arm64 architectures, consuming 30-50 MB RAM at idle with SQLite-backed message caching. Integrations include Grafana, Prometheus Alertmanager, Uptime Kuma, Home Assistant, and Ansible Semaphore. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 / GPLv2 dual-licensed.