Hi Dhammika, I directed you to this forum so others would benefit from my/any response.
1. In Moodle mobile 3.5, is it require to set up the development environment?
Yes. I have the whole ionic/server/chrome thing as described here
2. is it need to develop a remote add-on for the plugin to mobile support?
The terminology has changed, but as of 3.5 you can put everything in your plugin. You can see examples of the new way of doing it with
and
3. I am confusing how to start to Moodle mobile plugin development. So can you please mention steps need to do?.
It is confusing, partly because it is new and because there are very few examples. I have been working on updating my gapfill question type to work with the new plugin but have only got to the point of showing the output from a question and have yet to do the interactivity part. Having said that, if you are already a developer it is not specially difficult to learn how to to do this work, and easier still if you have some javascript/jquery/angular experience. I have had some very useful help and advice from some of the HQ developers.
4. Is there any template for Moodle mobile plugins can use for customization?
See my answer to question 2....
Please post again saying what type of plugin you are hoping to develop and you may get some more specific help.
Good luck