Target was the stock /bin/bash on every Mac, so bash 3.2, no associative arrays, no mapfile, awk doing the heavy lifting.
Two bugs worth sharing. First: ps -Aero rss,comm looks like "all processes sorted by RSS" but -r sorts by CPU. My "top 5 by RAM" list shipped sorted by CPU and looked plausible for days before I caught a 26 MB process listed above a 280 MB one. It's -m for memory sort. Second: grep -c prints "0" AND exits nonzero on no matches, so count=$(... | grep -c x || echo 0) gives you "0\n0" and an integer comparison error later. The fallback echo was the bug.
Per-app memory aggregation (summing helper processes per .app bundle) turned out to be a 12-line awk program. The sticky bottom progress bar is DEC scroll regions plus a WINCH trap.
