Gentle Bytes’ $10 Startupizer is one of those utilities that does one very specific thing, but does it well. The thing, in this case, is manage your login items—those apps and other nifty processes that you’ve opted to automatically launch or open every time you log in to your account on your Mac. Startupizer does this well by giving you greater control than OS X over exactly when and how those things launch. (Note that, confusingly, Startupizer doesn’t manage startup items, the system-level items that run when your Mac starts up. Rather, it manages only the user-level items that open when you log in.)

Normally, your list of login items sits buried a couple levels deep in the System Preferences utility (specifically, in the Login Items screen inside the Users and Groups pane). Once you find that list, there’s not a lot you can do with it: You can add items to it, and decide whether they should launch visibly or not, but System Preferences doesn’t let you otherwise control the login process.

Startupizer automatically detects any items (apps, files, menu-bar utilities) you already have in the official login-items list. You can then select which of those items should be managed by Startupizer. If you later add new items to OS X’s login-items list (say, by installing a new app and opting to have it launch at login), Startupizer detects that addition and alert you; you can then choose to move the new item to Startupizer’s list or leave it in System Preference’s list.

Once an item is in the Startupizer list, you define the conditions under which you want it to launch. Those conditions fall into three categories: date and time; modifier keys; and power source (battery or power adapter). So, for example, you could define a condition that says a particular app should launch whenever you log in between the hours of 9am and 5pm on weekdays. (You could call that condition Work.) Or you could define a condition that says don’t launch an app if you hold down the Option key at login. You can create as many of these conditions as you need, and then choose which ones apply to which apps.

As you’re configuring the conditions under which specific apps should launch, you can check your configuration using Startupizer’s launch-simulation mode, which shows you which items will launch when, for example, you log in at 10:00am on a Monday while holding down the Control key.

Startupizer also lets you define the order in which items open at login by simply dragging items up and down the list. So, for example, I’ve configured my items so that Bartender launches first, followed by the rest of my menu-bar apps. You can also insert pauses in the launch sequence—say, to give you time to remember to press a modifier key. Alternatively, you can configure a standard delay between every item in your list. You can also tell Startupizer to launch App B only after App A has finished opening. It’s the kind of control that can make your login sequence a lot saner—but without driving you insane with details.

I have a couple of complaints about Startupizer, but they’re fairly minor. For one thing, Startupizer lets you move items from its main list to an Ignored Items list—you supposedly manage items in the ignored list back in System Preferences. But in my testing, items I put in the Ignored Items list didn’t reappear in the OS X’s Login Items list.

My other complaint is more of a wish: As I mentioned, you can tell apps to launch (or not) based on the time or day, the status of modifier keys, or the power source. I can think of a number of other conditions I’d like to be able to use, such as the type of network connection or my geographic or network location. The developer says he’s experimenting with such additions, so this complaint might be addressed in a future update.

Otherwise, I think Startupizer is a dandy little utility, and it’s one that’s made my everyday computing life just a little bit easier and more controlled.

Want to stay up to date with the latest Gems? You can follow Mac Gems on Twitter or on App.net.