Some of our favorite apps (that we use all the time) are currently on sale on iTunes right now. If you're in the mood for an awesome calendar, need to handle PDFs like a boss or have passwords you constantly forget, pick up these gems now while they're on sale.
This is the second app I install on all my devices (the first being dropbox). With one password (hence the name) you can secure and easily access all your passwords, private notes and credit cards. Syncs with your Mac version too. Indispensable.
Taking pride of place on my home screen, this is the best calendar app I know of and I've tested a lot of them. First up it's gorgeous, second of all it's super well designed and lastly it uses natural language to create appointments. Enter, "Lunch next Wednesday at 1pm at Burger Up" and it will automatically enter all the appropriate fields automatically. There's also a version for iPad and Mac which I highly recommend.
Lists, lists and more lists. I love making lists. If you need a highly original approach to the to do list genre of apps look no further than Clear. This one purchase will work on your iPhone/iPad and they also make a Mac version too. It's not for everyone and while it has a tiny learning curve (that isn't too steep) it's a very slick app that's my to-do list of choice.
PDF Expert 5
The PDF market is a crowded one though there are lots of great apps made by talented companies. If tried a lot of them but settled on this guy. Don't be put off by its ugly icon as this is an incredible powerful app if you need to edit PDFs, take notes or sign documents. We bought our house using this app and use it nearly every week. Can't recommend it highly enough.