■ Functions.
Possible the following two launch methods.
(1) Launch by multiple taps of HOME or HOME→BACK.
(2) Launch by long-pressing the physical key and the number of times the key is pressed. Require physical keyboard.

Method that can be registered for launch
-Application
-Shortcuts
-Internal commands (screen lock, screen capture)
The following are only available for rooted devices.
-Letters input

■Use of Accessibility Service
The MultiLauncher uses the Accessibility Service API to collect physical key input information even when the MultiLauncher is not displayed.
The key input information enables applications to be launched by a long press of the key. The application can be launched without returning to the home screen, thus assisting the user's operation.
The information collected is immediately destroyed and is not stored, transmitted or shared.
Related video clips
https://youtu.be/wLco7AHxUmQ

■ Details.
(1) Launch by multiple taps of HOME or HOME->BACK
https://youtu.be/cd6ywHV3TlY
There is no upper limit to the number of taps that can be registered.
The HOME application currently in use can be used without modification.
To use this launch method, select ‘MultiLauncher’ in ‘HOME setting for OS’.
Select the HOME app you are currently using in ‘Settings of HOME App’.

(2) Launch by long-pressing the physical key and the number of times the key is pressed.
https://youtu.be/wLco7AHxUmQ
https://youtu.be/PIrg-YadJmQ
The number of apps that can be registered to one key is unlimited.
If your device has a dedicated launch button (convenience key), you can use the add-on TerrainLauncher to launch applications based on the number of times you press the button.

■FAQ.
Q When I press a key on the HOME screen, Google starts up.
A Set a modifier key or disable the Google application.

Q Other applications appear in the background of the start-up screen.
A Restart device.

Q User assistance services are not ‘running’.
A Restart device.

Q Sometimes it takes a long time until the start-up screen is displayed after pressing a phisycal key.
A Android specification. This can be avoided by specifying MultiLauncher in ‘HOME setting for OS’ and the HOME app to use in ‘Settings of HOME App’. The HOME app in use can still be used.

Q There is a physical key launcher, BlackBerry Launcher.
A Personally, I think it is higher functional than the BlackBerry Launcher.

■Setting procedure
Refer to the following.
http://ssipa.web.fc2.com/index_android.html
http://ssipa.web.fc2.com/index_multilauncher_hkey.html
http://ssipa.web.fc2.com/index_multilauncher.html

■Others
If you have any requests, please comment on Google PlayStore.

Screen-less launchers