Under app store on your phone, look under updates. At the top it will say purchased, with a little arrow in a circle. You tap on that, & every app you've ever owned will be listed, & you can reinstall it on your phone from there.
If you have a iTunes backup file, you can recover your data by extracting from iTunes backup file, if you don't have a iTunes backup file, you can retrieve from your iPhone directly. This guide would help: http://tinyurl.com/ms5zh8a.
34 minutes ago
Last edited at 10:27PM on 3/6/2014
I too have experienced something like this on a smaller scale. There is one note that my phone just doesn't like and keeps deleting. It's a recipe and I know for certain I haven't deleted it myself. Luckily my iPad had it saved through iCloud, but this is actually the second time it has been deleted. I suspect it may have happened when I performed a soft reset to my phone, but I'm unsure. A soft reset is the only thing I've done in the last few days that I can think of that was significant. http://tiny.cc/uj9bcx