You can enable article sharing without having the article content on your own web site or requiring a DPS web viewer. You can use social sharing with a dynamically created Social Share landing page created by Adobe DPS using metadata and assets you provide.
To enable sharing, check "Enable social sharing" in the DPS Portal (Project Settings > Basic tab). Upload a brand image on the same tab if you want your app logo/image to display at the top of the Social Share landing page. You will also want to provide your app store URLs on the Store tab if you want buttons to display at the top of the Social Share landing page to enable users to install your app.
The remaining information used in constructing the Social Share landing page is in Content & Layouts portion of the portal. In Article Properties, you'll see a URL created and displayed in the Social URL field. This is the URL that will be used to share and will result in the Social Share Landing Page. You do not need to provide a URL to your web site.
In Content > Article Properties > Image, you can upload a Social Media image. This image will be used in the Social Share page and in the share posts (e.g. Facebook, Twitter, Email). If you don't provide this image, the article image will be used.
In Content > Article Properties > Social, you can provide some article text to give your users something to read. If you don't provide this text, the Article description will be used. You can also include an additional Web URL if you want an additional link on the Social Share landing page (this is optional). Leave the Social Share URL as-is (the URL created by DPS) and the Social Share landing page will be seen by users who receive the social share.
The Social Share landing page also uses Article Title and Author. The page will also display information from 3 other articles within the same collection.
It sounds like you're looking for the Web Viewer, which is a representation of the DPS 2015 articles in a desktop browser. The Web Viewer is not yet available. At this time, when you set up social sharing in your iOS app, the share link will either jump to a web article (which you don't have) or to a landing page. It sounds like you'll want to wait until Web Viewer is supported before you enable social sharing in your app.