I'm following this article: https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_qs_customobject.htm on how to create a custom object. I am not seeing the create | custom object item anywhere in the lightning experience. I am a project admin in the org so I do not think this is a permissions issue. This is for a developer org, is that why I do not get the option? 

Hi

We are new to the salesforce and we are implementing to integrate our app data to salesforce.And we are in confuse to work with SOAP API or REST API which is better because when we try to work with Rest API we are succesed in creating an Account, Lead but when we try to convert a lead to account but we failed.And also we read few post reagarding Rest Api saying that Rest Api doesnot support lead conversion is it right?
If it support lead conversion would you please let us know how to work on it using httpwebrequest.

And also let us know which Api is the best one to work with salesforce to integrate to our App.

Regards
Vinod