Here are the apps I use for online poker. If you have any questions, feel free to .
-Sam

PokerTracker
PokerTracker is a database engine. It's incredibly powerful, but you should know that. Make sure you're using the SQL back-end and are patched.

PokerTracker costs $55 and it's the best investment you could ever make. There's a 1k-hand trial.


PokerAce
PokerAce is a heads-up display for PokerTracker. It reads your database, grabbing important statistics on each player and paints them on your poker window. It works on every site PokerTracker reads.

PokerAce is currently free, but will cost $25 for the next version.


     
There are mods for both the underlying graphics for the client as well as the layout for PokerAce.

If you're a total data-junky, you can try my setup. I use a card mod and my adaptations of APerfect10's layout and a black graphic mod. It's not for the meek, but you get used to it. (I promise.)


PokerGraph
PokerPatterns is a grapher for PokerTracker. I have examples here.

PokerPatterns is currenly free, but you should donate.


MultiTable Helper
MultiTable Helper impliments a queue of tables, bringing the active table to a specific location on your screen. It also implements keyboard commands, so you can use (f1,f2,f3) for (fold,call,raise). MTH currenly only supports Party and skins.

MTH is crucial for small screens, but I still like it with lots of space. Besides real-estate management, it's worth it for the keycommands. I also like having the window I care about moved to the front. It takes some getting used to; it makes it harder to follow hands you're in if they keep getting whisked away. The thing is, if you're massively multi-tabling, you're not tracking the hand between actions anyway.

MTH is currenly free, but you should donate. Don't 8-table without it.


PartyMine
PartyMine is a data-mining app. You specify which limits you care about, and it opens as many tables as possible and leaves them open so Pokertracker can watch the hands. If a table loses players, PartyMine closes it and opens a new one, so you can leave it open while you sleep.

PartyMine also does networked mining, so your desktop and laptop can both mine without overlap. Share the hhf folders on the laptop, and the desktop can collect data on both at once. If you're not logged in (if you have more machines than accounts), you can open 1 table on each site. If you are logged in, you can open 10 on Party and 4 on each of the other skins. That's a whole big bunch.

PartyMine currently costs $30. There's a 5-day trial.


AllSnapAllSnap
AllSnap is a tiny app that forces windows into a grid. I actually run it all the time, but it's especially nice when you have tons of windows open (like PokerTracker, PokerAce, MTH, iTunes, and 8 PartyPoker windows).

AutoHotkey
AutoHotkey is a scripting tool for Windows. I use it to load all the above apps at once, and to map keyboard commands for poker. It's an incredibly powerful tool. Here's my script.

AutoHotkey is free, which boggles the mind.