How to use "external" programs on the HP Prime

[wotar]

Hello everybody,

I am completely new to using this type of calculator. After playing around with the Prime for a few days, my excitement is unfortunately gone. The reason for this is that I cannot get installed external programs or apps to work. Also, I couldn't find any explanation on how to use programs with this calculator. The manual doesn't cover this topic either (at least I can't find it). All I can find are tutorials on how to write programs (which I definitely don't want to do right now) or how to install them on the device.

More specifically: I've downloaded, properly installed and tried several apps and programs, but to no avail (okay...except for one periodic table app). It's not even clear to me whether I have to select a specific app before I can use a specific program. As far as I know, the computer always needs to run an arbitrary app as a base in order to do something. But how does it work in conjunction with these “external” programs?
The only program I could get to work (AC Basic Electronics) blocks the device! I think I need to reset the calculator to get it out of this program. All other programs just give me a yellow exclamation mark when I try to start them. The apps I have installed either report “syntax errors”, an orange exclamation mark or do not behave at all as described by the developer.

So the main question right now would be if anyone can give me a comprehensive guide on how to use programs with the HP Prime.