Hey HN, I routinely run out of RAM, CPU or GPU resources and wanted to know when it happens and what app was causing it. But, I didn't want my menu bar to turn into a row of numbers.

I just wanted a single line that tells me when something interesting happens (e.g. an electron app starts eating up all my RAM).

Comparison:

iStat Menus and Stats have lots of depth, details and modules.

ActivityLine is deliberately the other extreme: one clean line with app icons showing what app is responsible.

In auto mode, it switches to whatever is being used most (e.g. jumps to Network when something is suddenly sending or receiving data). You can also click it to change metrics or hover for a detailed breakdown.