Google Stackdriver Error Reporting - Aggregates and displays errors produced by cloud services
Logmatic - Logmatic is a log centralization, analytics & visualization platform to improve software & business performance.
Million.js - A fast, <1kb virtual DOM
Serilog - Backend Development and Utilities
Sentry.io - From error tracking to performance monitoring, developers can see what actually matters, solve quicker, and learn continuously about their applications - from the frontend to the backend.
LogTailApp - LogTail is a local and remote (SSH) log file viewer and monitoring application for Mac OS X. It is a pure, modern, document-based Cocoa App