🚀 go-pugleaf

Sure.  There are two categories of such utilities:

(1)  Switch to a particular application via keyboard.

Kerry Clendinning's EasyKEYS Control Panel
(info-mac/cp/easy-keys-15.hqx; 92K)

You assign one separate hotkey for launching/switchingTo
each one application/DA.   I set cmd-ctrl-T for NCSATelnet,
cmd-ctrl-E for ResEdit, cmd-ctrl-R for Rolodesk, etc.

I think CE Software's QuickKeys offers a similar capability.

Matt Mora's GoTo FKEY (freeware)
info-mac/fkey/goto-14.hqx; 7K

You hit the FKEY, then a dialog box appears, listing the 
running applications.  You type the first characters of 
the name of application you want to switch to, and hit Return.

There are other keyboard launchers that offer similar things,
including CE Software's DTLaunch (part of DiskTop package),
Matt Mora's another freeware LaunchApplication (info-mac/
util/launch-applications.hqx; 40K)


(2)  Hotkey that switches you to the "next" application.

Jeremy Roussak's Apollo 1.0 (shareware)
info-mac/ex/apollo-10.hqx; 372K

One hotkey switches to the alphabetically-next running
application.
Another hotkey switches to that application, too, but
after 'Hide'ing the current application.
Apollo has a LOT more features than just the switcher hotkey.
Highly recommended.


David Lamkins' PwrSwitcher Control Panel (freeware)
info-mac/cp/power-switcher-10.hqx; 40K

One hotkey switches to the next application in the order
the apps had been launched.
Another hotkey switches to the _previous_ application in
that order.
Yet another hotkey "sets" the current application as "marked",
and another hotkey toggles back-and-forth directly,
between the current app and the "marked" app, afterwards.
(This last feature is a VERY handy one when you want to go 
 back-and-forth between two particular apps, while you are
 running lots of apps.)


There are several other similar utilities, but these two
are the best ones, as far as I know.

Cheers,

Mark
--
Mark Nagata
nagata@kurims.kyoto-u.ac.jp