Hi.. it is me that asked the question... had to register to respond....
@Soundtallica - Thanks for trying to help but I think I must have explained myself badly as you appear to not be talking about the same thing I am... though I am a noob so maybe I am just not seeing that functionality you are talking about by not using it correctly.
Either way I have found a solve.
SOLUTION
- Go to GooglePlay and download the free "HOME BUTTON LAUNCHER"
- Go into SETTINGS/APPS
- Click the cog icon
- Click "default apps"
- Click "assist and voice input"
- Click "assist app"
- SELECT "Home Button Launcher" from the list.
Now when you long press the home button it will load the launcher. This is a small windows box that you can populate with as many apps as you like. A kind of quick link to a folder of apps if you like but in the settings for HOME BUTTON LAUNCHER you can set it to automatically load an app if it is the only app added to the list.
This effectively means that you can now set LONG PRESS on your home screen to instantly load any app of your choice.
Problem Solved!
side note - I use Nova Launcher )have for a long time. If you use Nova Launcher you can go SETTINGS/HOME and select NOVA LAUNCHER from that list. Then in the Nova Launcher-Settings/Gestures and Inputs click on the HOME button and select an app to launch or some other options you find there.
This will effectively mean that pressing the HOME button when you are already at home will launch an app of your choice through NovaLauncher, and LONG Press will also launch an app or app draw of your choice. This dose not affect the default functionality of pressing home to go to the home screen and minimise the current app to background.
For example I have the home button long press bring up my sms app and clicking home when I am already at home launching my browser.
If you do not use Nova Launcher, I am not sure what app will populate the list in settings/home... but I am sure there would be other small apps you could find similar to Home Button Launcher that are not entire desktop ui like Nova launcher dose.