Locked down for your "safety", your iPhone is designed to operate the way Apple intended. With recently relaxed app store policies and great strides within the jailbreaking community, however, you can add great functionality that Apple never wanted you to have.
VLC Media Player
It's still hard to believe the day came where VLC was approved in the app store. Originally just for the iPad, VLC was released as a universal iOS app just a few days ago. While using it with high-definition MKVs gives you a clear indication of why Apple doesn't bother supporting other formats, VLC's performance with standard definition files — particularly DiVX AVIs — was basically flawless. (More performance notes here.) Regardless of performance, however, VLC opens up your iPhone to nearly any video format you'd want and that's enough to praise all by itself. Plus, it's free. [iTunes]
Where VLC Media Player fails, AirVideo and StreamToMe pick up the slack. Although VLC adds support for many new video formats, your iPhone can't necessarily play them (or at least play them well) plus video takes up a ton of disk space. Air Video and StreamToMe are both great solutions that allowing you to stream content from your computer's hard drive to your phone over Wi-Fi or 3G. They convert content on the fly so it'll play nicely with your iPhone, allow you to essentially watch whatever you want regardless of the format. Each app has a few features the other doesn't, so they're not identical, but overall they're both very capable of handling your streaming video needs. If you want to make sure you're fully covered to watch anything, regardless of Apple's support for the format, either app (both $US4) will serve you well. [Air Video / iTunes]
Wi-Fi Sync is my favourite jailbreak application and entirely worth the $US10 it'll cost you. I don't really care for iTunes in general, but when syncing is necessary it just seems so archaic to sync a Wi-Fi enabled devices with a cable. Wi-Fi sync cuts the cord and lets you sync your iPhone over your local Wi-Fi network. It's surprisingly quick when compared to cable syncing and setup is very easy. You just install the Wi-Fi Sync application on your iPhone and your Mac or Windows PC, pair your iPhone with your computer and start syncing. You're not limited to a single device either, so if you happen to have an iPad, for example, you can use Wi-Fi sync to sync that too. [Wi-Fi Sync]
While the apps above cover the major missing features of the iPhone, there are still a few niche, awesome apps that serve a more specific purpose. We didn't want to leave them out, and so they've found a place in the honourable mentions.
- SNES HD (Free) - SNES HD isn't so much an iPhone app as it is an iPhone-iPad app combination. It turns your iPhone into an SNES controller which you can pair with your iPad. It's a neat idea for people with both devices, but if you're just looking for a straight-up SNES emulator for your iPhone, snes4iphone is the way to go.
- Winterboard (Free) - Apple likes to control the look and feel of your iPhone, but you can circumvent those limitations with Winterboard. You can use it to apply your own, custom theme to the iPhone's home screen interface, or you can download and install one of the many existing themes available on the Cydia jailbreak app store.
Got any great "evil" apps, available in iTunes or Cydia, that you love? Let us know in the comments.