I would recommend an app called 'DU battery saver'. Just look it up in the play store, and you should be good to go.
To fix WiFi problems with your Samsung Galaxy S3, try changing your WPA connection.
You can send your Samsung galaxy S 4 back to the manufactures for cracked screen fix.
Fix it.
Get a new battery its probably your battery.
You can fix your Samsung Galaxy Ace if it keeps restarting by restoring your phone to its original factory settings. This wil take your phone back to its original settings and get rid of the restarting problem.
You can send your Samsung S 4 back to the Samsung company to be fixed if you cracked its screen.
Without any details as to what is wrong with the phone, it is hard to determine.
Yoyo honey singh
If your USB charger port is broken on your Samsung Galaxy S phone, you will have to disassemble your whole phone, and solder a new connector on to the phone's motherboard.
You will have to reset your username and password in your settings.
Pictures on your Samsung Galaxy s3 appear to be blurry due them being compressed by your telecom provider being sent to your phone but if you turn on your WIFI the pictures will be sent directly to your phone and therefore most likely not blurry.
if the screen is black you cant fix it is an internal crack that spread to the external part of the phone.