If you're interested in chatting with friends on the fly without having to be on your mobile device, then you should definitely check out Messenger and Chat Lock. If you're not familiar with this application, it allows you to lock and unlock your chat windows from either an SMS or MMS message sent to your phone. If you receive an SMS from a friend on their phone and you don't want to share your personal information, you can set it so that your friend can not send you any private messages. It's a simple and easy way to ensure that no one has the ability to read any of your personal conversations. You can also use it on your rooted Android phone to ensure that you always have access to a chat window on whichever device you happen to be on.
These two apps are useful for testing various features of software like messenger, RIM BlackBerry, HTC Evo and other proprietary programs for the Android platform. These types of software are very complex and it requires real-time testing to ensure that the application performs consistently across multiple platforms. However, if you're interested in simulating an OS like Windows, you can use the same type of software by installing messenger and chat lock onto your android emulators and use them. This will enable you to test your application on a variety of hardware configurations to ensure that it performs consistently across different devices.
There are a number of third party developers that have made similar apps for the Android platform. You can find a number of them on the Android Market if you're looking to use these types of "proto-emulators" to test various software. However, if you're interested in having both messenger and chat lock or in one application, then you should invest in a dedicated android development company that has created several different applications that do everything that you need. By purchasing one of these premium apps you'll get an extensive range of features and functionality, along with the added convenience of being able to lock your phone with ease.