I agree with sleepychu. The interface was largely intuitive and laid out. The text at the top looks like a tab based interface and I too tried to click to go back to the edit step. Even having definitely seen the "cook" button (hot pink! yay!). Personally I'd buttonize (!) those texts top-center and add "cook" before share. You should probably consider changing it from "cook" to something more obvious - make, finish?

When I look right and left I see other elements of the interface off-screen, but again clicking here does nothing; seems like these should be active areas that move to the relevant "tabs".

It looks like you're probably going to add user accounts as a premium option? Seems like a possible monetisation. There's a company that turn gifs in to hologram gifts I think, might be a good tie-in, or they might license your editor.

When reddit get hold of this your server is going to explode with memes. I'd take a cue out of imgurs book and roll with that - add a top listing, hot now, etc. in form of thumbnails; consider allowing comments.

Lastly, I assumed that the giflr link would both share my gif and give a prominent remix option, but it didn't seem to do the later, I could clearly just start a new gif and insert the old one but that seems a bit clunky.