Hi,
Using the debug commands on the search bar, you can create launchpad-like functions on K5. You can create a new debug command such as ".XY" that will execute any .sh script you want. Please see the post
https://www.mobileread.com/forums/sho....php?p=2167928
Also, you can make the Kindle Store button execute an application or set a parameter with one action. I found this to be the easiest for an action that I perform many times as it requires only 1 or 2 taps. You can also make it perform different actions with each tap.
Please see the same post as above.
Thanks,
James