Last year I downloaded (vsn 2.6) and tried it for a month. Here's my Review:
( Note: Apple's built-in App-Switcher is: [apple]+[tab] )

(+) PROS:

• + Multiple Hot-Key Activation Choices
• + Right-Mousers can more easily activate it ( e.g., [control]+[tab] )
• + And Likewise Left-Mousers ( e.g., [control]+[return] )
• + You can EASILY step-navigate through Apps by releasing and pressing the 2nd Hot-Key key (to Reverse direction press the [shift] key as the 2nd key instead).
• + Right-Click an App's icon to see Contextual Menu Options (or use Keyboard Shortcuts INSTEAD)
• + Provides MANY Options you can set in System Preferences

(-) CONS:

• - Can NOT [esc] from it IF Hot-Key is set to: [apple]+[tab]
• - If you've just hidden an app and then quickly depress and release the Hot-Key, it re-activates the Hidden App. It should NOT do that. What it should do is Select the Next ACTIVE App below the one on top (which is standard OS X behavior).
• - Developer never responded to my Important Email Inquiry (and why I never bought it)
• - NOT updated since 7-06 (1.5 yr)
• - When Intel Macs were released it took 1-YEAR for an Intel-compatible update
  

* SUMMARY ( RATING: 3 / 5 ): A real Time-Saver. It makes app-switching easier & brings new useful features into this process.

IF the Developer was responsive to emails and updated this app more frequently I'd raise my rating to 4 / 5.

What would Help? This proposed Enhancement would save a lot of time when many Apps are open: SEGREGATE Active and Hidden Apps into Distinct Groupings wherein Active ones are navigated first. Either:

1. Place Active on LHS and Hidden to the RHS, OR
2. Place Active on Top and Hidden below in a 2nd list

CRUCIAL to any software purchase is the Developer's commitment to their customers needs and wants. If a Developer is not giving adequate consideration to customer needs; and is not planning ahead of the upcoming OS changes; then their product is not a worthy investment.

* USAGE TIP: In order to confidently rely on the use of the [esc] key I recommend you NOT use [apple]+[tab] as the designated Hot-Key.