I gave a go at signing up for Goko recently and was reminded of why I still play on isotropic. So here are some things that bugged me going through the sign-up process & initial games, with suggestions about what to do instead (because hey, being constructive is good).
At registration time, as far as I know it's still true that if I don't sign up with Google+, then I can't ever get Walled Village. I prefer not to use my social media accounts for sign-ups in general, but that's not really the point. It displays a lack of respect for your users to not let them pay you money for the game. Same goes for the unlockable promos, for that matter. I suggest making a promo pack available for purchase.
It's apparently still not possible to buy, in one purchase, exactly the number of Goko coins needed for the mega pack. Why not? Seriously guys, don't make it awkward to buy your stuff. Maybe some combination of smaller clumps of coins can do it, but why even make it that complicated? I suggest allowing Goko coins to be bought in any quantity, or failing that, at least in the quantities that correspond to stuff you want to spend them on.
Text layout on cards is messed up. For example, Ironmonger. Compare side-by-side the Goko version and the IRL card. I have attached both for your convenience. The Goko version has not enough space between lines of text. For example, the d in "discard" overlaps the y in "your". Also the options at the bottom are not grouped together like they are in the real card. This is super minor, I admit, but hey. I suggest tweaking the display to look like the real cards, or even better, getting someone with typography knowledge to have a crack at making them nice.
The log button still doesn't toggle the log. Clicking the button shows the log, but clicking it again doesn't hide the log. In my opinion, it would make the log a ton more usable for this to be a toggle.