Here's a quick songwriting tip that can save most of your song ideas.
Store and organize your songs shouldn't take you a lot of time. In fact, using both Dolby on, and Evernote is a really quick and easy process.
So if you want to be carefree about your next song ideas and demos, make sure to give it a try.
Dolby On - https://www.dolby.com/apps/dolby-on/

Dolby On is a great way to record song snippets, and ideas.
It’s easy to use and has some neat audio processing tools, that can really help to polish up an amateur phone recording.
Evernote - https://evernote.com/

I’m kinda biased to say anything about evernote.
It’s been my daily driver for worktasks for solid 5 years now.
I really love using it, and I found it to be the best place around to store all my demo ideas.
Another big plus, is that your .wav or .mp3 files can be safely stored on Evernote’s cloud.
The best thing in my opinion is the simplicity of the whole proccess.
I hope this can help you out.