I do this too.
However, I would recommend writing your ideas down on paper, using a pencil/pen. There's something about the physical act of writing that (for me, and I've read research into this too) works better than typing into a Phone/Computer.
I'm as plugged-in as the next buy, but I've certainly noticed that not only am I able to let go of the idea better when it's on paper, but I also tend to elaborate on the idea in more detail (helping me later) when I write on paper (in numbered notebooks is my preferred method) - and I can draw diagrams/sketches too, which is even better.