3 - track energy usage rate
4 - formalize message format and protocol
5 - tests (design is starting to take shape, so it is time)
6 - show how many Debian package updates are available
7 - show how many Debian package security-updates are available
8 - monitor disk usage rate of change and alert if suspiciously fast
9 - bring back CPU usage monitor
10 - status bar templating language
11 - retry/cache for sensors fetching flaky remote resources (such as weather)
12 - throttling of broken sensors (constantly returns errors)
13 - alert specification language
15 - above/bellow/equal to threshold value
17 - snooze time (if already alerted, when to re-alert?)
20 - totals (grand and per state)
25 - memory leaks (if some process consistently grows)
26 - is select process up?
27 - log resource usage of select processes
28 - monitor arbitrary HTTP endpoint availability
29 - is status within expected range?
31 - is responce time within acceptable range?
32 - report detailed status upon request (to a terminal)
33 - use color to indicate age of data
35 - totals (per time period)
41 - monitor battery time remaining
42 - monitor accuracy (is percentage change rate on track to meet estimate?)
43 - adjust estimate based on observed inaccuracies in past estimates (Kalman?)
47 - [x] actual METAR parser, to replace the flaky `metar` program
48 - Replaced it with a parser of NOAA's XML API (piping `curl | hxpipe | awk`)