No matter how many features OS X borrows from iOS, one big difference Mac and iOS users is that we want to know what's going on under the hood of our computers. Where you might be content to quit a wonky app or restart an iPad, on your Mac you want to investigate the problem up close and personal, even tracking page outs and diving into crash logs.

Apple offers such tools as Activity Monitor and Console for monitoring system performance, but Bjango has always understood that this information is most useful when it's instantly at your disposal, not tucked away in the Utilities folder. With the fifth version of its popular iStat Menus app, the company has improved on nearly every aspect of the multitasking menu bar monitor, bringing the interface in line with Mavericks and Yosemite, and putting a greater emphasis on which apps are slowing you down.

Whether you're a longtime iStat fan or a first-time user, you'll immediately be struck by its modern look. From the settings to the dropdown graphs, no pixel has been left unturned, and a modern, minimal elegance pervades every element. iStat's wealth of information has been thoughtfully calibrated and organized, and all of your data is even easier to see at a glance. And if you're running Yosemite (and its accompanying dark menu bar and Dock feature), iStat will blend right in. The classic white background is still available, but once you see how vibrant the various graphs look using the black theme, you'll have a hard time switching back.

While it's wonderful to look at, iStat 5's improvements are more than skin deep. Dive into its menus and you'll find an array of new performance statistics, including advanced multi-core CPU and GPU monitoring, improved battery tracking, and more control over network status. There is also a greater emphasis on memory usage. iStat takes full advantage of the color-coded compressed memory and memory pressure indicators that Apple introduced in Mavericks.

But where iStat 5 truly excels is in its handling of individual app performance. Much like iOS 8 will show you which apps are draining your iPhone's battery, iStat will break down CPU usage, network access, and disk activity for individual apps, and call out any energy or bandwidth hogs so you can deal with them appropriately. It does the same for RAM usage, though I would have liked to see the inclusion of an "optimize" button to quickly alleviate some of the strain.

Along with the mountain of statistics in your menu bar, iStat can also replace your Mac's battery icon with its own supercharged version. You'll find graphs that track your power consumption as well as the condition of your battery and the cycle count--all useful things that are otherwise hidden in the System Information utility.

iStat's Time menu could easily be sold as a standalone utility. Digital horologists will certainly get their $16 worth: The dropdown menu goes far beyond hours and minutes, providing everything you could ever need to know about your day--from the current azimuth angle of the sun, to when it will set, and which phase of moon will appear in the sky. The maps and charts are gorgeous to look at, and with data for more than 120,000 cities, it'll likely be just a matter of time before it replaces your default OS X version.

The other icons, however, are an acquired taste. I'll admit I'm not a huge fan of menu bar doodads, but I do keep a few up there to help with my workflow. With iStat, each menu has its own set of live icons that give real-time feedback as you work. Bjango did a fine job with updating them to match the app's new look, but the concept is still a bit too distracting for my tastes. Thankfully these are all optional; iStat's excellent customization panels let you choose exactly what you want to see, and I have my dropdown menus boiled down to a single clean icon.

Bottom line

Whether or not you want to busy up your menu bar with iStat's numerous icons, there's no debating its usefulness. Its bevy of monitoring and diagnostic menus will keep you apprised of every little thing going on with your Mac--and, perhaps, cause you to visit your Utilities folder less frequently.