Take apart interlocking blocks in Armor Games’ stunning 3D puzzle game, Interlocked. We also have a sing-along app that will get you into the Christmas spirit, and an interactive book full of classic nursery rhymes.

All app prices are subject to change at any time and without notice regardless of stated free duration. Price changes are solely under the control of the developers.

iPhone:

Foolproof Art Studio for iPhone ($1.99 → Free, 17.1 MB): Turn your favorite photos into beautiful oil paintings with this fun effects app. You’re able to import a photo from a variety of sources or snap a new one in-app. Then just drag your finger all over the canvas to add an oil painting effect. The faster you move your finger, the more blurry the effect will be. The app also includes the option to customize the brush size and effect. You’re able to save your final creation as an image and share it via a variety of social networks, or you can save it as a movie file to put each stroke on display.

Foolproof Art Studio for iPhone is available for free for a limited time. It has a 4.5-star rating with a total of 21 ratings.

iDocs Pro for Google Docs™ and Google Drive™ ($4.99 → Free, 9.0 MB): Manage your Google Docs and Google Drive with this productivity app. Once you’re logged into your account, you’re given full control over your files. You’re able to add, edit, rearrange, share, and store files within folders. The app syncs with your account in real-time, and allows you to jump between different accounts in a flash. The app also includes AirPrint support, search, and the ability to prioritize files by starring them.

iDocs Pro for Google Docs™ and Google Drive™ is available for free for a limited time. It has a 3.5-star rating with a total of 74 ratings.

Universal:

Interlocked ($0.99 → Free, 19.2 MB): A stunning 3D brain-teasing puzzle game. Each puzzle presents you with a group of interlocking blocks, and your job is to take them apart as quickly as possible. You’re able to rotate the structure by swiping outside of it, and you can interact with the blocks by swiping over them. The game includes four chapters, 36 puzzles, and achievements via Game Center.

Interlocked is available for free for a limited time. It has a 5-star rating with a total of 19 ratings.

Christmas Carols for Kids, Sing Along Songs – Jolly Jingle ($2.99 → Free, 34.9 MB): Get into the Christmas spirit with this sing-along app. It includes five festive songs, each with their own set of lyrics, interactive environments, and variations. The lyrics will scroll across the top of the screen so everyone can join in on the fun, and you can jump between the variations by tapping the note icon in the top left corner.

Christmas Carols for Kids, Sing Along Songs – Jolly Jingle is available for free today only (12/08). It has a 5-star rating with a total of 47 ratings.

iGeeky – Gadget News and Tech Updates ($1.99 → Free, 13.7 MB): Get the latest news from your favorite tech blogs with this geeky app. The app includes feeds from 23 of the most popular tech blogs, including everyone’s favorite, AppAdvice. You’re able to scroll through articles with a swipe, and read a quick overview for each before heading to the official page. You can also share the news via Twitter, Facebook, or email.

iGeeky – Gadget News and Tech Updates is available for free for a limited time. It has a 4-star rating with a total of 12 ratings.

Global Tuner ($1.99 → Free, 14.0 MB): Get almost any instrument in tune with this music app. You’re able to select any one of the 39 included instruments by sliding your finger across the bottom of the screen. Then play a note and watch as the circular tuner lights up. The app includes 128 kinds of tunings, accuracy up to 0.1 cent, four built-in skins to choose from, and the ability to import your own image to be used as a skin.

Global Tuner is available for free for a limited time. It has a 4.5-star rating with a total of 27 ratings.

Nursery Rhymes with StoryTime ($0.99 → Free, 88.4 MB): An interactive book filled with classic nursery rhymes. Each page is jam-packed with interactive items and characters that can be flicked, pulled, and tilted. The eight nursery rhymes are strung together, so the fun never ends. The app includes optional audio narration, and gorgeous artwork.

Nursery Rhymes with StoryTime is available for free for a limited time. It has a 4-star rating with a total of 165 ratings.

iPad:

Star Rain HD ($0.99 → Free, 177.1 KB): Manipulate stars and colorful particles with this interactive visualizer. You’re able to position your stars anywhere on the screen. Then tap to unleash loads of colorful particles and watch how they interact with the stars’ gravitational pull. Stars can be rearranged at any time, and the particles will respond to their movements in real-time. The app supports up to nine stars on the screen at once.

Star Rain HD is available for free for a limited time. It has a 4-star rating with a total of 14 ratings.

Stocks with Tapfolio HD ($3.99 → Free, 5.5 MB): Visualize your stock portfolio with this intuitive finance app. You’re able to quickly add stocks to your portfolio by looking up their symbol via the menu on the left side of the screen. The app will then display the stock’s recent performance in graph form. You can minimize or expand the range of the stock graph via gestures. You can also add transactions to monitor your holdings by tapping on a spot on the graph. The app includes the ability to compare stocks, and the ability to track gold, silver, and US mutual funds.

Stocks with Tapfolio HD is available for free for a limited time. It has a 3.5-star rating with a total of 217 ratings.

That concludes today’s issue of Apps Gone Free. If you like staying on top of these daily deals, don’t forget to check out our free AppsGoneFree app. It provides all the deals each day, and even an archive of past deals that are still active.

Developers:

If you are a developer who would like to get your app included in our “Apps Gone Free” daily lists, here’s our basic set of rules:

  • It must have at least a three-star average rating at the time it goes free.
  • The app must not have been free numerous times (3+) over the last six months.
  • The free version of your app must not include ads.

To submit an app, simply send a request to tyler@appadvice.com with the subject “Apps Gone Free.” Please include the name of the app, a link to it in the App Store, when and for how long you intend to offer the app for free, and anything else you would like to share. We will take it from there.