I've used Conky on Debian GNU/Linux years ago and it refreshes data every X seconds. It just parses data from e.g. /proc and displays this in a UI. The default UI and settings sucked balls though with some tweaking I could get something akin to a nice widget on my desktop. Although modern DE's have nice widgets or applets which allow you to do the very same though. Ie. I enjoy the nice graphs of System Monitor 2.30 on my laptop with GNOME right now. Merely graphs, no names. I know the colour each graph represents, and in the case I forgot I can hover over it and get the information in plain good ol' English.

Now, back to Conky. On your phone, Conky would refresh every X seconds, too. Even though you're not looking at it. If I run htop in an X terminal it will refresh even though I'm not actually looking at the data. The only time it is useful to refresh is when 1) logging data (slow to write to flash though, and a CPU hog, too) 2) when the user is seeing the data. IOW, say I have a UI on my phone, and I have a battery applet. This applet should not refresh when I am not looking at my screen. However, the phone should receive calls even when my screen is not displaying anything, and it should alert me and allow me to interact with the phone when I do receive a call. Now, on a desktop, server, router you may get away with stuff like SNMP, RRDTool, Conky, and what not. On a laptop it may be preferred because you simply put the device to sleep mode or hibernate mode when you stop using it. A phone however is never put in sleep mode, since it has to stay up, allowing you to be reachable. So you'd have to SIGSTOP it.

This is a prime example of a (desktop/console) application which isn't suitable for a device which is normally running on battery and isn't imba on juice power. I've had a similar thought about an RSS feed widget too (and OMWeather; a weather widget), but I don't remember I solved that problem optimally since the device cannot know whether it should update or not. The device can be told it should update every X seconds (from 5 seconds to 30 minutes to never) and that is it. End of story. To tackle this you'd need to use complex data analysis currently unavailable. Examples include: 1) where is this user going to, and should I try to update OMWeather for this 2) should I update RSS feeds for this user now since he isn't roaming (he is in his home country) but he will be roaming for 6 hours in a neighbor country according. Such can be calendar based. You could even base it on the next target re-juicing. But really, we are far from there yet and while I have to concede Conky might be the best tool for the job you're trying to fulfill I wouldn't recommend running it 24/7; I recommend to use battery applet and system usage for general usage, and trying to abstract the important information to simple yet informative, small GUIs (users dont want to read to learn this information) whereas allowing the user to have a check under the hood with e.g. Conky to get informative, extended information in good ol' English. You shouldn't have to check your system resources the whole time in English since it'd be distracting, taking too much time and effort to read it. Instead, it should be abstracted which is exactly what my GUI examples are doing. That was my point.