What’s new and noteworthy in the world of Apps this week?

Here are a few updates, deals, and new apps worth talking about.

Day One is on sale

The very best journaling app for iOS and the Mac, Day One, is on sale for the holidays. Right now the universal iPad + iPhone version of Day One is just $2.99 and the Mac version is just $7.99.

You can read our full review of Day One here.

New Podcast app: Castro

A brand new podcast app just came out for the iPhone. It’s called Castro, and it’s very well done.

Dan Benjamin, the founder of the 5by5 podcast network, is quoted saying: “Podcasting apps are so tough to get right. I’ve tried them all, and Castro fits perfectly with the way I like to manage and listen.”

And John Moltz, who is one of our contributing writers at The Sweet Setup, likes Castro quite a bit as well. In his short review of the app, Moltz wrote: “But if you think I wouldn’t drop $2.99 on a great app for listening to podcasts — in fact, the best I’ve used — well, then you don’t know how much I spend on apps.”

Castro is inexpensive ($2.99 at launch), the UI’s use of blur is stunning, and it’s very snappy. Moreover, it has a very clever timeline scrubber — just slide the bottom play controls to the left or right to quickly fast-forward or rewind to a certain spot in the podcast episode you’re listening to.

However, our pick for the best podcast app remains Pocket Casts because of its impressive feature list and the availability of native apps for iPhone and iPad.

Castro is currently iPhone-only and does not (yet?) have features such as syncing, OPML import, and playlist creation. To add podcasts that don’t appear via Castro’s in-app search, you need to use this URL scheme. If you don’t need (or want) the robust features Pocket Casts offers — and many don’t — then Castro won’t do you wrong. It’s simple, delightful, and easy to navigate.

Update to Loom

Loom is our favorite Photo Stream alternative, and it was just updated to version 1.2. First off, the recent 1.1 update brought some changes to the photo Timeline view and added several new features, such as image de-duplication (not showing duplicate photos in the main timeline), quick previews when in Select mode, and Private albums (which keeps photos in those albums out of your main Timeline view). The 1.2 updated added the ability to view video within the timeline. Loom is also now offering an incentivized referral program — inviting your friends and family members to join loom will get both of you an additional 500mb of photo storage.

Coming soon: a review of our favorite PDF app for iPad

For the past two weeks we’ve been testing and researching PDF apps for the iPad. We’re now finishing up our review and will be publishing it soon, but we’ll let you in on our pick ahead of time: The best app for managing, editing, and reading PDFs on your iPad is PDF Expert 5. It offers the fastest PDF reading experience and the most robust tool-set available on iPad.