Ram Monitor

And a Battery view, one tap away:

• Your Mac's power at a glance — charge level, time remaining, live power draw in watts, how fast the charge is dropping, plus battery health and cycle count, read straight from the hardware.
• Energy use per app, ranked from most to least, with the same Apps, Helpers and Other filter. Each row shows how hard an app is working right now and the total CPU time it has used since it launched.

macOS doesn't publish a per-app battery figure to any app, so the ranking is based on CPU time — the same measure Activity Monitor's energy score is built on. RAM Monitor tells you that plainly instead of inventing a number.