Wattagio is powerful battery assistant. It informs you about current battery health and helps to decrease power usage. Flexible settings in the application give you options to customize your profile to meet your needs.
Battery Indicator is a macOS app that shows the remaining battery time in your menu bar.
Battreminder is a light-weight minimal browser extension, which lets you track your laptop's battery level and reminds you with a sound notification when the battery is fully charged!
NetData is a system for distributed real-time performance and health monitoring. It provides unparalleled insights, in real-time, of everything happening on the system it runs.