Best 23 Open Source iPhone Apps & Source Code

The iPhone platform now has more than 100,000 apps, and they're almost all available through the iTunes App Store. That's an amazing rate of growth, and it shows how rich the iPhone platform is for developers. Of course, this list can't possibly be comprehensive. If you're comfortable with having everyone know where you are at all times, go ahead and try those apps out, too. Here, though, are my first favorites.

1. Diceshaker - little dice-rolling utility for your roleplaying sessions and board games. It's designed to be simple, uncluttered and easy to use. source code
2.  Last.fm - Listen to more than 5 million tracks for free with Last.fm on your iPhone. Create personal radio stations based on any artist or genres, and listen to commercial free music for hours. With Last.fm on the iPhone you can also check out artist bios and concert information and share your favourite tracks with your friends using the iPhone contact list. source code
3. ABC 123 - " Simple in concept. Brilliantly addictive. Maddeningly challenging." - TheYoshi
Memorize the sequence of letters or numbers. The sequence will then be covered with bubbles. Pop the bubbles in the order of the sequence to beat the level. source code
4. Mobilesynth - open source classic monophonic synthesizer, designed for live performance. Developers are encouraged to visit the website and contribute. source code
5. Gorillas - Gorillas is a port of the original GORILLA.BAS to the iPhone platform. It's a turn based single player game where the objective is to blast your opponent away using carefully aimed bananas. source code
6. PocketFlix - With iPhone and PocketFlicks you can find movies and manage your Netflix information, all while on the go. Heard about a great movie from a friend of yours? Whip out PocketFlicks and add it to your Netflix queue with just a few clicks. You'll never forget about a movie you want to watch now! source code
7. Sci-15 HPCalc - The SCI-15C is the most accurate and precise emulator of the world-renowned HP 15C RPN high-end scientific programmable calculator available for the iPhone and iPod Touch. We use the *exact same* mathematics and calculations of the original to give you reliable, bug-free, precision and accuracy that you can trust. source code
8. Task Coach - This is the iPhone version of the open-source Task Coach desktop application. It features basic task editing and synchronization with its desktop counterpart over the network. source code
9. Tweejump - Tweejump is a jumping arcade game inspired by many wonderful games including Icy Tower, Doodle Jump, PapiJump, and others. source code
10. Freshbooks - MiniBooks Lite puts the popular web invoicing software FreshBooks in the palm of your hand. Manage your clients, send invoices, run timers, and record payments, all while on the go. Plus, MiniBooks Lite fully synchronizes with your FreshBooks account, so you have access to your account even when you're off the grid. source code
11. Colloquy - Colloquy for iPhone and iPod touch puts the power of the most popular IRC client for the Mac in the palm of your hand. Built atop the Chat Core framework, Colloquy Mobile is a full featured client optimized for the on-the-go experience. source code
12. Doom Classic - DOOM Classic includes the original three episodes as well as Episode Four, Thy Flesh Consumed, spread across 36 levels of non-stop carnage and action. source code
13. Molecules - Molecules is an application for viewing three-dimensional renderings of molecules and manipulating them using your fingers. You can rotate the molecules by moving your finger across the display, zoom in or out by using two-finger pinch gestures, or pan the molecule by moving two fingers across the screen at once. Double-tapping on the display lets you switch visualization modes. source code
14. Packlog - Introducing PackLog for Backpack. The easiest way to update your Backpack status and add journal entries right from your iPhone or iPod touch! source code
15. Wikihow - Bonus feature: The application includes the ‘wikiHow Survival Kit,’ a collection of articles to get you through life's most difficult situations. Includes articles on first aid such as CPR, the Heimlich maneuver, treating burns and bleeding. source code
16. Tubestatus - Get up to the minute service level details on all London Underground tube lines, DLR and Overground.  source code
17. Wordpress - Manage your WordPress blog from your iPhone or iPod touch. With WordPress for iPhone, you can moderate comments and create or edit posts and pages. All you need is a WordPress.com blog or a self-hosted blog running WordPress 2.7 or higher. source code
18. YourRights - if government agents question you, it is important to understand your rights. You should be careful about what you say when approached by law enforcement officials. If you give answers, they can be used against you in a criminal, immigration, or civil case. source code
19. Mover - Mover+ is the quickest way to move stuff from iPhone A to iPhone B, with style. Put what you want to send on the Mover table, connect via Wi-Fi or Bluetooth, and flick it offscreen where you want it to go! source code
20. NowPlaying - Added 'People Search' to Netflix. You can now lookup actors, actresses, directors, etc. and get their bio, filmography and additional details. source code
21. Natsulion - is a simple Twitter client for iPhone/iPod touch. It has simple, fast, and slick user-interface to enjoy Twitter. It's based on NatsuLion for Mac OSX and it's open source application, too. source code
22. Twitterfon - Echofon (formerly ‘Twitterfon’) is an easy to use, super-fast Twitter app for the iPhone and iPod Touch. source code
23. Tweetero - Twitter client with image upload support. source code