Usage is very simple. If you press and hold button on which HButton is assigned, names of selected applications will be shown in given order. When you will see name of application you want to start, just release button.

If you want, you can disable displaying names, and use only vibration or beeping.

You can see the usage tutorial here.

Update Description:
v2.2 (10-01-2008):
- <Toggle Sound (only WM5,WM6)>.
- <Toggle WiFi>.
- Fixed: list of applications on PPC2003.
- Fixed: directory browsing in HBSetup.

v2.1 (23-10-2007):
- <Toggle BT>.
- <Toggle SIP>.
- Fixed: refreshing top window after Rotate.

v2.0 (23-10-2007):
- <Rotate Left>.
- <Rotate Right>.
- Assignment to HW buttons could be done directly in HBSetup.
- Label configuration - size, font size, colors.
- Fixed: install dir in localized ROMs.

v1.9.1 (30-09-2007):
- <Back> - switch to previously opened application.
- HButtonTask - first item in list could be Today or previously opened application.
- Fixed: Device reboots when is used on "Programs".

v1.8.1 (07-06-2007):
- Fixed bug with param parsing.

v1.8 (07-06-2007):
- Added some applications.
- <Ok/Close> (minimize app).
- <Quit> (terminates app).
- <Start Menu>.

v1.7 (06-06-2007):
- Fixed bugs with PHM keys.
- Possibility to start application with params.
- HBSetup search for links in linked directories.
- HBSetup doesn't assign .lnk file, but parse it and assign exe with params.

v1.6 (02-06-2007):
- "Today" application.
- HButtonTask - task switcher like alt+tab. (first app is always today).

v1.5 (25-05-2007):
- Please uninstall previous version (not necessary on WM5, WM6).
- Fix: Bugs in installation and setup on devices with localized ROMs.
- Fix: Unable to remove first app in list.
- Fix: Not working for some buttons on Universal.
- Could be installed on Storage Card (Only HBSetup.exe).
- "Clock" application.
- Positioning of info box.

v1.3 (22-05-2007):
- "unlimited" num of apps on one button.
- "None" application.
- Option to cycle thru applications.
- Option to notify first application.

v1.2 (18-05-2007):
- Contains new options for starting applications: vibrate, beep, display name on screen.

SOURCE

http://hbutton.pavlicek.org/

Reviews:

***** [Apr 25, 2009] by daddydave using Dell Axim X51v
Just to clarify what I said in my review, the hard reset had nothing to do with HButton, it just meant I had to install HButton again and reconfigure it.

***** [Apr 23, 2009] by daddydave using Dell Axim X51v
Fantastic program, similar to Duh Button Launcher for the Palm OS. Multiple applications on one button without having to memorize bizarre double or triple clicks like competing programs. Great program. It can be configured for a default (press-and-release) action (make sure the app is at the top of the press-and-hold list and it seems like there was a box to check as well.) I have this installed on a Dell Axim X51v. My wireless button is now a multipurpose toggle for wi-fi, Bluetooth, my useless Email button is now the Todos/Notes buttons that Dell forgot, and the Home button toggles between the MortButtons versions of Programs, Settings, and Tasks.

A few minor nits to pick:
I could have done without the pixel perfect control of where the application names show up on the screen, but hey, set it up once so that it is visually pleasing to you, and it's done. One user error that I keep committing repeatedly and consistently for some reason is to assign apps to one of the HButtons, then leaving the Assigned to field to a physical button. No doubt this provides flexibility, you basically have an inactive button filled with apps ready to be enabled at some point, I did a hard reset and reinstall recently and I spent way too much time on this user error because I thought I had remembered to assign the HButton to a physical button.

**** [Feb 21, 2008] by andorpapa using MDA Vario (WM5 --> WM6)
I like touchscreen, but most of the software's aren't stylusfree jet, and there are 5 hardware button on my Vario, let's use them! So HButton is a good choice to control the phone. I can launch any programs on my device by pressing 1 button. Nice feature is the delay selection too. On my Vario, the "Toggle WiFi" doesn't work, it says: "WiFi not found". It's interesting, because Toggle BT and other command (like Rotate etc.) works flawless. Maybe the not official WM6? It's a good software, it gives more freedom to use the hardware buttons, so keep on developing!

***** [May 28, 2007] by Ylan using Wizard (HTC)
Great app, keep it up! But can I suggest having a feature to run programs that are not in the programs list? the one with browse program??? Thanks again.