It is ALL about extra functionality for me. I have a few things that simply enhance the look of my phone but I'm not about bogging my phone down with heavy "visual" modifications.
I like that I can just open my phone app, type in a name (T9 functionality) and swipe through the list of number that correspond to the letters I typed with my phones dial pad, instead of opening the Phone.app, tapping Contacts and scrolling through the contact list til I find the number, which still requires a couple taps after that.. (remembers which numbers you call often so you only have to swipe through the numbers to find the right one once or twice. Tho you can always just finish typing the name, and it always shows)
I like that I can reply/compose/forward/delete an SMS/iMessage from anywhere on my phone (including the lock screen) without having to open the messages app
I like that I can just swipe up from the bottom of the screen to activate my app switcher, and swipe any paused application up and out of the app switcher, instead of double pressing the home button, tapping and holding on an icon til it wiggles, then tapping the minus sign. 2 swipes. Love that. very quick and easy.
I like that I can pull down notification center, and toggle off/on WiFi/Bluetooth/location/rotation lock/LED flash light/volume/mute/vibrate/brightness/private browsing in Safari/reboot/respring and all without cluttering my notification center. (can also do this on the lock screen)
I like that I can assign almost any slide/tap gesture and series of button presses to perform any cation I want. Literally.........ANY action.
I like that when I get an incoming call.......I don't get interrupted with an "answer/decline" screen. A "notification banner" like banner just comes down allowing me to continue what I'm doing. I just swipe left on the banner to ignore the call, or swipe right to answer it. If I answer it, I can just tap the speaker button, and still continue what I'm doing, and all telephony functions work, including the proximity sensor turning the display off when I hold the phone up to my ear.
I like that I can lock any individual application I want, and have many customizable options for that function.
I like that I can tether to whatever WiFi capable device I want without paying for it
I like that I can change literally any UI image I want (if i chose to anyway)
I like that on my keyboard, I can swipe from the space bar to certain keys that I have enabled certain text for. I tap and hold on the space bar, drag my finger to the "@" key, let go, and my email address is entered.....and I like that I can assign any key on my keyboard to do the same thing with whatever text I choose.
I like that by pulling down notification center, I can view how much data I have used compared to how much i can use daily in a small bar in notification center.....always allowing me to see how much data I can use without going over my 2GB limit.
I also like that I have a snooze/stop button on lock screen and springboard when an alarm or timer.lol
I like that i can "truly" make an application run in the background instead of being paused like only stock iPhones can do
I like that I can block pretty much any advertisement in apps with ads in them
I like that if I tap on a link somewhere by accident (like the Mail.app for example) that a prompt pops up asking if I want to allow the link to open in Safari instead of it just opening Safari (or any other app) automatically.
I also like that tapping on the Weather Widget in notification center just toggles on location services for Weather.app instead of opening the Weather.app automatically.
I like that i can move multiple app icons at one to when I'm editing my springboard icon layout.
I like that I don't have that stupid "Store" button in the Music & Videos apps.
I like that I can download music from the web, and add it straight to my iPod library with all album art and info rite on my device
I like that I can download any YouTube video I want, and save it to the Videos.app. Can also download videos in mp3. More free music!
I like that I can remove the Voicemail tab in the phone app. I like that because i use YouMail from the AppStore.
I like that I can FaceTime over 3G
I like that I can view literally "ALL" content of my device. The same Cydia application that allows me to this also allows me to send any song from my iPod library to anyone via email.
I like that I can assign any application to open via the camera button icon on my lock screen.
I like that because I am jailbroken, I can fix that annoying "double tone" bug in 5.0.1 along with fixing the slight delay in the copy/paste actions.
I like that I can place as many apps as I want in one folder, and scroll through them up or down (even tho I don't use that specific feature with this tweak)
I like that I can view my running applications in pretty much whichever way I choose (besides viewing them in the app switcher)
I like that when I'm listening to music (which I do a lot) that all I have to do is swipe left to skip a song, right to previous song, slide up to turn volume up, swipe down to turn volume down, and double tap the screen to play/pause when I'm at my lock screen. Very useful for driving, as you don't have to look at the screen. Just wake up the phone, and swipe to control playing media.
I would name the rest of the stuff I have, but they are "visual" modifications, and don't really do anything for 'functionality" since i was only trying to state the added functionality a jailbroken iPhone can have.
I like that I learned to type with Morse code, which allows me to text when I'm driving (don't recommend BTW) without having to look ate my phone, as I am typing with sound. A cydia tweak that has a plug in for a typing game (that comes from the AppStore) that allows you to learn Morse code very quickly
Well................This is why i jailbreak.
Can do loads more stuff than that with a jailbroken iPhone, but those are just the tweaks I like and use.
What are the apps you use for these functions? Many of these seem very good.
