Filger is a very minimal buff/debuff tracking addon that will allow you to track buffs/debuffs on yourself, target, pets, focus, etc, and also can be used to track cooldowns.
Buffs/debuffs/cooldowns can be displayed as both bars and icons, and stack sizes and durations will be shown.
Only the buffs/debuffs/cooldowns you want will be displayed, the addon uses a whitelist system and you have to tell it exactly what you want it to show.
Preset spell lists for all classes are finally included, although they're not all inclusive and may be missing a spell or two here and there.
The default config is VERY bar/icon spammy, you'll probably want to go through and comment out a bunch of stuff for a usable setup.
All configuration must be done by directly editing Filger.lua, there are no config screens or slash commands.
Moving the bars
Open Filger.lua with a text editor and change local configmode = false; to local configmode = true; and reload your UI (/console reloadui). You can then hold down shift + alt, and drag the individual anchors. After positioning, you can reset configmode to false and reload your UI again.
spellName = The name of the spell you want to display, duh!
size = The size of the icon/height of the bar.
scale = Overall size of the icon/bar.
unitId = Which unit you want to display this bar for. Can be a number of units, player/target/pet/focus etc, take a look at the included entry for Earth Shield to see how you can display a bar for specific units only.
caster = Who cast the spell. You can limit the icon/bar display to spells cast only by a specific unit, or display no matter who cast it. Handy for displaying only your own sacred shield for example.
filter = BUFF, DEBUFF, or CD. Fairly self explanatory.
barWidth = The width of the bar.
Copying/modifying existing entries is the easiest way to get started.
Filger is a modified version of Filger, customized to fit my own UI, all credit goes to Shantalya!