I created an simple app that exposes a button to call a particle function.
My motivation was to have a quick and simple way to open my garage door.
I published the code as open source and the app is available on Google Play as “Particle Buttons”.
You can create multiple buttons to call your particle functions. More info here.
Looking forward for your feedback
p.s: if you are interested to have it on iOS, let’s chat (It’s ready to publish as it was written in Xamarin, but Apple charges a significant fee to publish).