I spent my summer of 2013 developing my first Android app- NetLive.
It allows you to monitor your internet data transfer rate while also showing the app that is using the most data at the current moment. It runs both in the notification drawer or as a widget, so you always have access to your transfer rate information.
I stopped development for awhile, but these past few months I have been hard at it. Initially I was only going to update it to support Lollipop, but I ended up basically rewriting the whole thing to address the main gripes many users had.
Unfortunately, I had to drop support for Android versions before 4.3 because it was causing many users serious issues. Basically, I am using four API calls that may work on Android versions prior to 4.3, but it is not guaranteed. As a result, in previous versions of NetLive I was using a hack to get around this, but it was causing major battery life issues for some devices. It was a tough decision, but I think the best move was to drop support for those users that were getting a bad experience. For those curious, the API calls I am referring to are from the TrafficStats class: http://developer.android.com/reference/android/net/TrafficStats.html
Particularly these four methods: getTotalTxBytes, getTotalRxBytes, getUidTxBytes, and getUidRxBytes. These methods all give the warning: "Before JELLY_BEAN_MR2, this may return UNSUPPORTED on devices where statistics aren't available." JELLY_BEAN_MR2 is API level 18 which is Android 4.3.
All feedback you can give me is much appreciated:
Google Play Link: NetLive
Check out the source code here: https://github.com/octohub/NetLive
[19 February 2015 - UPDATE V3.0]:
•Lower Ram Usage
•Lower CPU usage
•Lower Battery Usage
[3 March 2014 - UPDATE V2.5]:
• NetLive is now open source
• Streamlined settings
• Added share and rate options in menu
[22 February 2014 - UPDATE V2.4]:
• Bug Fix (thank you Jérôme)
[14 February 2014 - UPDATE V2.3]:
• Added V2.2 changes to the widget as well
[14 February 2014 - UPDATE V2.2]:
• Active app is now disabled by default, and also offer battery usage warning if it is enabled
[13 February 2014 - UPDATE V2.1]:
• Option to hide the notification icon
• Option to display total speed value
• Widget can now be added to the lock screen
• Bug fixed that would prevent the active app displaying in the widget if disabled in the NetLive notification
[13 February 2014 - UPDATE V2.0]:
• Notification icon changes whether you are uploading and/or downloading data
• The poll rate can be customized
• Bug fixes
[15 January 2014 - UPDATE V1.1]:
It has been a long time coming, but I have finally pushed out my first update. I have streamlined the settings, significantly reduced the APK size, and also now prevent my notification icon from taking up your precious notification area space. Many XDA users requested this, and I now use a low priority notification (like Google Now), which is available on Android 4.1 and up.