Assistant for android is a voice assistant (yeah, just like Siri if you were wondering) by speaktoit, which is free of charge and is available on the google play store. You can also upgrade to the premium version in which you can actually teach your assistant. That is you can create your own commands for your assistant.
Let's start with customisation. To say it in one sentence, that developers really knew what they were doing. You can can change your background to update with the home screen wallpaper or you can also put in any other picture from your photo album. Then comes your assistant's voice.
You can either stick to your phone's default synthesiser or you can buy a voice ( like a good one) from a variety of ounces which the developers are selling in app for $1. Now to your assistant itself. You literally build your assistant's avatar from scratch and you have a wide ( like really wide) range of options to choose from.
Now to the actual functionality. This app can do almost anything. ( except bake you a cake). If it does not know an answer, it will offer to ask your Facebook friends for it and even offers to read their replies. The GUI is really nice. Oh, and did I tell you about the jokes? I think the developers have a good sense of humour. This app even offers interactive knock- knock jokes which will keep you entertained for a long, long time.
This app also comes with different sized widgets for your home screen which are pretty useful. So, to sum it up, this is a great app ( except it can't bake you a cake) and the best part is that it's free! I think that is one of the best voice assistants on the App Store and I definitely recommend this app.