Interesting update to Apple’s often overlooked HTML5, CSS3, and JavaScript authoring tool for iAds: you can now create iBooks Author widgets, iTunes Extras, and iTunes LPs, alongside regular iAds.

You can create an iBooks Author widget for use in your iBooks Author projects. For example, you can create a widget that allows users to stream video from the Internet, draw using their finger, or interact with a timeline.

More information about iBooks Author support in iAd Producer 4.0 is available here. You can also find documentation for all the new features on the app’s official support page.

iAd Producer was first released in December 2010.

Pupil looks like a nice app to switch between multiple resolutions on a Retina MacBook Pro. The core feature of the app is a configurable menubar item that can list the resolutions you use the most, letting you instantly switch between them.

I can’t try Pupil because I don’t have a Retina MacBook Pro. However, Roman Loyola’s review at Macworld is positive. Pupil is $5 and there’s a free trial available.

I also like how you can “test” Pupil’s menu on the website.

Big update for Twitterrific today, including automatic theme changing based on local sunrise and sunset times, automatic timeline refreshing after posting a tweet or DM, and improved VoiceOver support. The list of updates is long, but the rest is comprised of bug fixes and various improvements.

By the way, if you’re looking for those Trends, they’re buried in Search under the Tweets tab. For Favstar, you’ll also have to turn on those links in the Settings under Other Services.

For more information on Twitterrific, be sure to read our earlier reviews.

Another neat web app following the release of Forecast.io last month:

Forecast Lines shows you the forecast spread for each field (temperature, precipitation intensity, pressure, etc.), overlaid with our best guess of what will actually occur. It’s a simple idea, but a powerful one: at a glance, you can see what will happen over the course of the next week, and where we are most–and least–confident in our predictions.

Essentially, Lines looks like a consumer version of Forecast.io’s API raw data sources, which is also available here.

I’m a big fan of the Dark Sky team’s work with web apps and developer APIs for weather data. I can’t use the main Dark Sky app in Italy, but I am testing various third-party apps that are implementing Forecast.io and I’m impressed with their accuracy so far.

I like the idea of Lines’ statistically-aggregated graphs, and, unsurprisingly, the iOS web app is solid.