Who says that instant messaging is dead? This free app lets you send unlimited text and picture messages to all of your friends in an IM-like environment. WhatsApp Messenger requires a somewhat annoying setup but has millions of members for you to chat with. Though you'll eventually have to pay a nominal fee, it could save you big if you have a limited texting plan.
When you install the app, it makes you use your real phone and verifies it through a text. The process takes anywhere from 2 to 5 minutes to complete. This may be a little annoying, but it helps friends who are using the app find you much more easily. Once you're done setting up, the app has a very clean interface without ads. To support itself, the app asks you to pay $1 a year after your first year of free use. This may be a little unusual, but it's definitely a small price to pay for a sleek app. As for the actual messaging, WhatsApp Messenger mimics an SMS layout and makes it very simple to attach images and other media to your messages.
If you have enough friends who use the app, it's an awesome way to avoid text-messaging fees. If you don't have many friends who use the app, it's worth it to spread it to all of your friends to help them save. It doesn't consume enough data to worry about overages, and it combines all of the best features of instant and text messaging into one powerful app.
Editors' note: This is a review of the trial version of WhatsApp Messenger for Android 2.8.1504.