tutorial of android app developing

I would suggest to rather buy book like Reito Meier Professional Android 4 Application Development or Apress Beginning Android 4 as their introduce you in structured way to topic where online tutrials are likely to be just cream swooping and failing to give more of background and more in depth info. It is your call, but I would say these book are better investment than any tutorial out there

yes i agree with you peter. better to buy books than search for online tutorials, they are not good enough.

I would highly recommend you take a look at The Busy Coder's Guide to Android Development. The book is written in a easy-to-read manner and covers almost all the features Android currently supports.
For every topic presented in the book you get an explanation first, then a step by step tutorial that shows how to implement explained things.

Also, you may visit my blog: https://androidresearch.wordpress.com/ where I periodicaly publish Android Tutorials.

There are number of free tutorial available on internet. And also learn "Professional Android 4 Application Development hy Reto Meier". I hope its helps you.