many thanks for your quick response quys - I'll try to go through it
So, it all depends on what data you are sending via these HC-05 Bluetooth Modules.
I'm sending a single "char" from my phone to the module to trigger certain programs for the LEDs. So like for example an "A" is sent and I will recieve multiple chars like "GREEN" as validation from the module. So it's a very basic serial communication.
In the end I would like to be able to send this char simultaneously to all 5 HC-05 modules.
The limitation exists with how many you can connect with concurrently
So far I was able to connect with two HC-05 modules as described via two seperate apps and a dual app mode on the phone.
Then you can basically connect with each HC-05 Bluetooth Module, send/receive the data and disconnect and then connect with the next etc. You could automate this process.
As I already said, this is not quite an option for me as it would take far to long to cycle through all the 5 modules. Also, it wouldn't be nescecarry to write an app for this - this could be easily programmed within the modules itself. Anyway, thanks for the advice for the MIT App Inventor, I'll check it out.
You probably haven't, as this implies that phone has two Blueteeth, and I bet it doesn't.
Oh but I did. I was able to connect to two HC-05 (and a bluetooth headset) all simultaneously. I also tried both of the serial communications - all fine. That's why my question was basically just about an alternative app.
Similarly, use a master Arduino to handle multiple HC-05s - only for the desperate.
So you mean like setting up 5 master HC-05 (controlled from one master arduino) to speak to each one of the 5 HC-05 slaves individually? This would indeed be quite desperate - but possible yes. I'll think I'll give the App inventor a try first.
Also many thanks for your hardware suggestions. I'm sure they will come in handy for someone reading this post who is about to do something similar. For now I would like to stick with the hardware setup I have. It wasn't originally intended for this situation but there are some dependencies to cases and permissions. That's why changing something on the hardware side would be a lot of effort. Anyway - I would be happy if you could take care of using the word "dumb".