But fact that they closed comments on their tweet don't look good.
Looking a bit further, it's more concerning that i thought,
1. They never disable comment, even on tweet about maintenance.
2. Using twitter search result (
https://twitter.com/search?q=ExpressCryptoIo&src=typed_query&f=live), @ExpressCryptoIo don't bother reply any user question (such as estimated time).
I still hope that they will come back .... I still have a balance of dogoins on my tap, this indicates that the api keys are working
And if they do come back, i strongly recommend you to withdraw your coin to wallet where you have the private key.