When ideas come faster than execution.

I am currently working on a web app but recently an itch to create something new suddenly appear.
And now here I am again confused whether (a) to pause the development of the main app so that I could scratch the itch of the new app, (b) to hold on for that idea until I finished the main one, or (c) to develop both things in parallel.

I think "a" would have the biggest motivational boost but anxiety about the main app might creep-in later. "b" would be the most rational approach but might slowly drain my motivation for ignoring an itch. And (c) is highly prone to burnout.

Just wondering what would be your approach for such situation?