Electron only works for desktop applications and probably needs a js-framework to work good. I think that React + Electron looks like a nice combo and then you can use React Native to create Android and iPhone apps also, probably sharing a lot of code between all versions.
+1 on this, I'm having a very pleasant time working on a couple Electron+React apps right now. I've been starting my apps based off https://github.com/chentsulin/electron-react-boilerplate but diverging greatly after getting it running.
Instead of react native you can also just reuse the UI-code directly for the mobile deployment. Just add meta tags like apple-mobile-web-app-capable=true and style with @media-rules.
To be fair "just" might be over simplifying things a bit. I've been doing this for an application and thinking that it actually would be a benefit to have a different code bases for the desktop and mobile editions. It can be a bit challenging to design for both targets at once.
At the moment the pairing seems to be Electron + Cordova for non-React JS frameworks; with those two you can share 100% HTML at least if you have a responsive CSS design.
Also, now that React Native is extending into the Desktop space more directly (with Linux, Mac, and Windows UWP variants), for React you may not need Electron at all.
Further aside, I'm also amused and unsurprised that engineering has been going into React Native for Web [1] so that with React Native you might not even target base DOM React again.
Electron is ok for certain applications, but I'm really wary of this whole trend. It's leading to extremely buggy, resource intensive desktop applications.
Electron - Build Cross-Platform Desktop Apps With HTML, JS, CSS
http://electron.atom.io/