There's a new app called WiFiMan that tracks wifi usage for iPads and iPhones. It's in the AppStore. D/load Meter tracks both wifi and 3G.
View how much mobile data you're using To see how much mobile data you've used, go to Settings > Mobile Data or Settings > Cellular.
Checking App Data Usage in iOS
You can find out how much data you've used just via Personal Hotspot in the Cellular/Cellular Data view. Tap System Services at the bottom, and all the iOS uses, including Personal Hotspot, are displayed.
To view usage on your device, go to Settings > General > [Device] Storage.
Open the Settings app and tap Cellular, near the top of the list. Then scroll down to the list of all your apps and find FaceTime in the list. Under the name of the app, you'll see how much data it's used this billing period.
To check and manage data usage, from the home screen select the Settings app. Note: To check your current month's data usage dial *data# (*3282#) on your mobile phone to receive a text message with the current bill cycle's usage.
Open the Phone app on iPhone and navigate to the Keypad tab. Then dial #3282 (#DATA) with the pound symbol included and press the green Call button. You should get a message right away with your current data usage for this billing cycle.
Press Settings. Press Mobile Data. The total data usage is displayed below MOBILE DATA USAGE. The data usage for each application is displayed below USE MOBILE DATA FOR.
How to check your cellular data usage on an iPhone
Open your iPhone settings.
View & Manage Data
To check your current month's usage on your Android phone, go to Settings > Connections > Data Usage. The screen shows your billing period and the amount of cellular data you've used so far. You can also set a mobile data limit on this screen.
Hop over to "Settings" and open "Battery." You'll see a breakdown of when your battery was in use and which apps are using up the most juice. You can look at the past 24 hours or past 10 days. There's also a section called "Battery Health." Click that for a quick analysis of how used-up your battery is currently.
Tap "Battery Usage." 3. Make sure you're on the App tab. You can scroll through the list of apps on your phone and see what percentage of the total battery each of your apps is currently using.