IPhone 4s 1GB DATA? How much app time can i actually have?

I just purchased an iPhone 4s, I have 250 mins and unlimited texts with 1GB of data.

I only really use apps such as instagram, facebok, twitter etc.
How much time can i actually use on these?

I don't want to go over and pay more, I'm already paying £31 a month

Added (1). So if i'm connected to Wi-Fi i won't use any data?

Is iphone 4S screen resistant scratch?

I've owned my 4s for 6 months from now and first day i got it, i asked the staff to put me a screen protector on it, so they did, but with time it starts to remove and its really annoying and bothers me when i use the phone, so i end up removing it all, i'm not thinking to buy another protector cuz i read that its resistant scratch, so please iphone 4S users help me, IS IT SCRATCH RESISTANT OR SHALL I JUST GET A PROTECTOR?
Pc:
If i wanna get a high quality screen protector i kinda get it from a really far far away place like it took me one hour and half to get there! And its quiet expensive its 15 pounds per one.

IPhone ios6 update restore

I tried to update my phone today but I had to do it through iTunes as the software was so low that I had no choice to. Anyway I did it and it didn't work and on the phone there was a picture of a USB and the iTunes logo and the only option was to restore it. I restored it and it said iphone could not be restored 3014 I don't know what it means I'm so upset is it broken? Am i going to have to get a new phone?

My iPhone has somehow locked so the screen will not rotate?

Phone screen stays oriented up and down, when rotated 90 degrees it does not orient side to side. There's also a little symbol up top with a lock with a circular arrow around it. I think it is locked and I can't figure out how to unlock it. Can anyone help?

Whatsapp keeps crashing when trying to open a photo?

I've been using Whatsapp for months now and never had any trouble. For the past few days when I try to open a photo the application crashes and closes down.

I've deleated it from my iphone 3gs and reinstalled it about 5 times now and it still not working. I've got plenty of space left in the memory and I've reset the phone, nothing is working.

Any idea's as to what could be wrong?

Best iphone case for iphone 5?

I'm hopefully getting my iphone 5 next week and i ordered the otterbox commuter case, i was wondering if thats good or if there's other that are better but low on price

Nervous about leaving home for two weeks?

I'm going to mexico with my boyfriend for 2 weeks in december and i'm really nervous.i've never been away from home for that long, let alone out of the country.i've been laying awake at night worrying about being homesick and missing my mom. The place we're staying at only allows an hour and a half of internet or something, should i bother to bring my iphone? I want to be able to message my mom some how is that possible? I know i can get an add on for international texting, is it risky to bring my iphone though? I'd turn off the data and all that of course. I'm really worried.

Is 100mb iPhone 4s data plan enough?

I'm looking into getting an iphone 4s and am wondering if 100mb of data is enough for me. I regularly check twitter and surf the internet. I would only go on youtube at home where this is wi-fi.