Edit: I have now gone to "AnyList" which, aside from being completely free, has a super fast and perfectly accurate syncing service, as well as a great UI.
The app itself is good. However the syncing service, which is imperative if my wife and I are able to use this, is simply too unreliable.
Ive had the app for a couple months, and liked it when it was just me using it. Over the last couple weeks Ive tried the syncing feature. I was quite disappointed to find it buggy and unreliable. Usually it works, but often items repopulate on the list (moments after they were deleted). Changes to the items themselves (editing categories, etc) often results in duplicate items on one decide, and deleted items on the other device. Its a shame the syncing werent better implemented.
Because we need to have a functional list that reliably syncs between our devices, we have now deleted Superlist and have gone back to ShopShop which, while not as nice to look at, syncs flawlessly every time.