Let me know what you think!
Nice design otherwise, looks cool!
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.
I know the state indicators up top (Add, Edit, Share) have caused some confusion when I've tested the app. Making them interactive is definitely an option I could look into.
"Cook" was meant as an informal description of what happens to the set of frames once that big button is clicked, abstracting that somewhat instead of making it the one big action might be an idea, especially as the app matures, the editing is going to mean more than the cooking.
I'm already thinking about how (or whether) to surface cooked GIF's, I want this to be able to be used as a platform for easy GIF sharing, where every GIF doesn't necessarily end up in the hands of the internet just because it lives on a server.
The remix option has struck me before as well, that might make Giflr able to tie into other services, make it like a general way to remix a GIF. I'll think on that one and see what I come up with!