Duolingo is pretty nice, but often the voices are odd and I'm not so sure the pronunciation detection is accurate. Hard to complain for a free product, of course.

Lingvist is fairly new and French-only for now, yet I feel like I'm making more progress with that than I did with Duolingo. Not sure why that's the case.

I'm pairing both with French vocabulary decks on Brainscape, which is an Anki-like SRS app. Lingvist claims it will switch to a paid model soon, and Brainscape decks are in-app purchases. Lingvist is both mobile and web, though I always prefer the web interfaces when I have access to them. Wish it also had a speaking component.

I've started using Verbling for having conversations but so far they seem pretty unstructured and not worth the money. This will, of course, depend on who you choose. There don't seem to be a lot of French to English options there.

If anyone has suggestions for alternatives, I'd love to hear them. I'd like to rapidly improve my French before a trip at the end of August.