I have simply a folder that contains 10+ text files, mostly containing numbered lists:
01_calendar; 02_TODO (just a stack of things I want to do); 03_questions (e.g.: "What substances emit sound when heated?"); 04_ideas (entrepreneurship, organization -- this is helpful because for one thing you start to see the pattern in your ideas -- what you value etc.); 05_opinions&thoughts; 06_self&improvement (my habits are like this and that, I could improve them like this); 07_read&watch&experience (list of interesting people, movies etc.); 08_my_history (contains critical events that have happened to me, it's really useful to see them all at once for self-reflection); 09_principles_I_follow; 10_humor (humorous ideas that I collect in order to create a stand-up routine someday)
Glad to be of help :). The list is by no means perfect, but has worked for me so far pretty well. I forgot to mention, that I have also folders with identical names for ideas that need extensive wording.
Hmm, since I don't have that many devices, and since I mostly write down my thoughts & ideas at home, I never had that problem. Maybe you could synchronize your devices & files with Dropbox for example.
