As also found in the official Google Android Market:

This application is a call minutes, sms, mms and data usage meter to monitor your credit usage. Never exceed your quota again!

Supporters unlock: free times/contacts/groups; widget; usage log; greater configuration of plan inclusions + more. A free 5 day trial is offered.

Please report bugs!

Please visit http://creditusage.matthewwardrop.info for more information.

Show your album art collection on the homescreen using the Android music library. Featuring multiple sizes, greyscale rendering, smooth scrolling and low CPU usage, this app is perfect for users who enjoy browsing their album covers as much as listening to their music.

Simple and statistical precision.

To help users understand their own mobile phone network data traffic usage, in order to better control the cost of data traffic.

2G/3G network data traffic monitoring capabilities.
The network data traffic to warn function.
The network data traffic statistics data display.

Paid version:
Monitoring data charts.
No ads.

Network Counter is Android (2.2+) application for monitoring of wireless network data traffic.

Features:
- Displays data traffic usage statistics for Wi-Fi and cellular / mobile networks.
- Possibility to setup an alarm for Wi-Fi and mobile data traffic usage.
- Network traffic statistics for currently active (running) applications.
- Ability to backup and restore of data traffic usage database.

Smart Data Watch is free app to monitor your network data usage and convert the usage as your currency also lets you to set quotas for daily,monthly usage

An arcade game similar to Peggle, that comes with a level editor and marketplace that lets you download/submit maps.

Measures time spent on each app. See which apps to uninstall because you're not using them!
The most accurate app usage tracker! Accurate to less than a second on Android 1.6 and up.

Beautiful, clean and elegant battery widget without unnecessary graphical clutter. Now in two versions: small (1x1) and wide (3x1).

Monitor Your Child's Phone from a Secure Web App or your Android Phone

ComQuotes - application with funny and interesting quotes by famous comedians like Mitch Hedberg, Dara O Briain, George Carlin, Dylan Moran, Eddie Izzard and more. Quotes are displayed in simple readable list format and can be easily added to favorites.

Cool green coloured live wallpapers. Columns of cubes are blinking with green color and there are green bubbles as well.

Are you fast? Are you passionate for really cool & smooth Games? Then this Super Ball Game is perfect for you.

A pure Open GLES game ensuring optimal battery usage and ultra-smooth functionality.

Catch Mole! is a fun game of puzzle and strategy with a Minesweeper style. Accept the challenge of Catch Mole!

Intraday Trend Indicator is a must have app for any investor who deals with any market index (for example Nasdaq). The investor is able to make nearly accurate predictions and take firm decisions using the app's calculated measures (Pivot Point, Resistance Points and Support Points).

AVG Mobile AntiVirus Security PRO for Android™ is AVG’s premium, full featured app that helps protect your phone & tablet from viruses, malware, spyware & online exploitation in real-time.

GreenPower battery saver brings many extra hours to your battery life!

"Charge less by extending your battery life with this amazing app""!! (Sprint newsletter)

Funny monkey with colored balloon and a lot of hearts.
Wallpaper Settings:
- you may change balloon speed.

Super Dj Vinyl Disk is spinning on your device.
Wallpaper Settings:
- you may change spin speed of vinyl.

This escape of funny little painted men never ends. They are running, jumping and fighting.
Wallpaper Settings:
- you may change escape speed of pistons.

You are inside the engine. Now you know how pistons work.
Wallpaper Setting:
- you may change rotation speed of pistons.