Vitals 

Activity Monitor lists a thousand processes, a hundred of them called Google Chrome Helper. Vitals adds every helper to the app that launched it, so you see 60 apps instead of 1,000 processes, each with one figure for memory, CPU, energy, disk and network. It keeps 30 days of history, alerts you when an app misbehaves, finds forgotten dev servers, and shows temperatures, fans and battery. Every readout can sit in your menu bar, arranged your way. Pay once. No subscription, no account.