I've been listening to a bunch of contemporary composers recently and an idea in that vein came into my head so my first project is to get that down and then try and develop it a bit.
My weapon of choice is FL Studio Mobile (currently it would seem in the middle of a big rewrite) as it allows me to get tune ideas down on my phone.
So I started off with a little arpeggiated piano line with some strings in the background. It was pretty easy to edit the notes and preview things - I find the mode changing interface a bit clunky to use, I'd rather things were more note based (i.e. chose a note then what to do with it rather than the current choose what you want to do then choose the note to change) but I guess I'll get used to it!
Anyway here are the results - enjoy!