I have been using Whatsapp since a really long time now, almost 3 years if I remember correctly.
This app used to be chargeable until a while ago however after it was taken over by facebook, they ended up making it a free app for life time! That was really cool.
I tried many messaging apps but in the end always came back to whatsapp.
I love the fact that it can be used to make free voice calls!
The cools things I like about whatsapp has to the simplicity of use, the app is pretty small in size, and is available to be downloaded for free with support for all devices and operating systems. I have tried installing it on Android old and new versions, latest Apple iOS and Windows phone 8. It also supports blackberry OS. It works like a charm.
Whatsapp is mostly used by me to send text messages and share pictures. It also sends videos upto 20 Mb. The one cool feature is that it also lets you send audio recordings and instant camera images through the shortcuts in the app.
The group option is also very useful! It now allows you to add upto 256 members in one groups and you can have as many groups as you like. I have made one for my official work as well!
There are a lot of apps in the app store which compliment whatsapp that basically allow you to customize your app as you like, it lets you change the backgrounds, add new emojis and even use it without a sim card!
I simply am addicted to Whatsapp and I shall continue to use it and enjoy the experience. I really hope it keeps adding new cooler features thorough timely updates!
Some down sides that I feel need improvement are it should support sharing of document files and increase the file size limit of video. Apart from that Whatsapp rocks! Totally recommended if you are not using it yet! all stars and thumbs up form me!