Android wallet does not work, neither the web wallet. On android I have just a blank screen all the time, while the web wallet, during registration, claims that a passphrace I've entered is not the same I was provided with.
Why isn't burst more popular? I believe it's a great idea.
Web wallets at burstnation.com seem to be up (It's under tools I think)... as someone else said there can be a delay once paraphrase is entered.
Regarding paraphrase... make sure it's EXACT when you enter it... no extra spaces etc. The paraphrase is your wallet.
Regarding why BURST isn't more popular... it really had no marketing up until 4 - 5 months ago. I still think it's tremendously undervalued.