I used to format my cell most offen. It is not possible every time to connect my cell to PC suit samsung kies & back up every thing.
The only important data in my cell phone is contact & sms history. So I can not afford to loose them. So I tried new android app called SMS backup & restore.
This app is available free of cost in play market. You can take backup of sms as well as MMS. There is also option to backup locally i.e. on phone or you can upload it to google drive / dropbox / email.
Also there is option to include Emoji / Special character in back up. Further It can back up n number of sms / mms.
When you are done with format of your cell phone, just install this app again. Give path of backed up file & it will restore all of your sms within seconds. Just one click & its done.So I am enjoying this app & satisfied with service. I would recommend it to every android user.