The popular Evernote desktop and mobile app today experienced a period of downtime, the company disclosed today.

The outage lasted a bit more than an hour. The company was looking into the matter as of 1:41 p.m. Pacific, when the company sent out of a tweet:

By 2:46 p.m., though, Evernote was back to normal, according to a status update. There was no immediate explanation for the downtime.

Evernote, based in Redwood, Calif., started in 2007 and has been on IPO watch for some time now. Last year Evernote said it had more than 100 million users.

Outages of the app are unusual — so much that the company sent out a follow-up tweet less than 45 minutes after the initial alert of the outage:

Last year the app went down after a distributed-denial-of-service (DDoS) attack.

Updated at 4:19 p.m. Pacific to reflect that Evernote’s app began working again an hour after it went down.