I have an iphone 4s for more than 1 year and yesterday i had 3gb free space.Today in the evening i have only 0,1gb(100mB) i connected my iphone with itunes on pc and it shows me that i have 5 gb on apps,photos,videos and i one more category (OTHER) which shows me that i use 7 gb!Please if someone could tell me a solution to this problem?
That much "Other" is corrupt data. You will most likely have to restore as a new device to get rid of it. Follow this by syncing your content back to your phone. You can first try restoring from backup, but that may not work given how large your other is.