With SharePoint 2013 on premise it is possible restore site collections out of a site collection backup (restore-SPSite). For those Site Collections the “Follow” Feature works perfect within the browser although all Site Collections have the same unique Site Collection ID.

Please change the “Followed Sites” Feature in the iOS app so it will work like within the browser.
At the moment we can’t use the iOS App because of our backup/restore rollout approach for new Site Collections. The app shows only one entry although I’m following several Site Colelctions.
My assumption is that within the App the Site Collection ID is used to identify the Site.

For the widely used approach of backup a Site template and restore it under a new URL, this won’t work.

*English follows Japanese
■Title(件名)：
SharePoint アプリでサードパーティー製Cookieを有効にする

Enabling third-party Cookies in SharePoint app

■Description(内容):
現在ネクストセット社のOffice365 MyPortalというアドオンを利用してサブサイトを作成している
iOS の SharePoint アプリから 該当の サブサイトにアクセスをすると "このページを表示する権限がないか有効期限がきれました
ブラウザーの設定でサードパーティー製Cookieを無効にしている場合は有効化してください" というエラーとなる。
ブラウザーのsafariから該当のサブサイトにアクセスをする場合は "トラッキングを無効にする" という項目を"無効にしない" に設定することで表示可能となる。
SharePoint アプリからもサードパーティー製Cookieを有効にする設定を実装することを希望します。

We currently create subsites using an add-on called Office 365 MyPortal made by Nextset.
When we access the created subsites via SharePoint app for iOS devices, we get an error stating “You do not have permission to view this page or have expired. If you have disabled third-party cookies in your browser settings, enable them”. However, there is no option to enable third-party cookies from SharePoint app. We can enable them by choosing “Do not disable” in “Disable tracking” option when accessing those subsites from Safari.
For improvement of usability, it will be great if we will be able to enable third-party cookies in SharePoint app for iOS as well.

Open links to sites outside of SharePoint.com domain in a browser by default. The SharePoint app doesn't handle 3rd party web app authentication well. For example, if you open your SharePoint Online site in the app and then select a link from a page in your SharePoint online site to your on-prem site, it gives a 404 error. The SharePoint app features also differ from what users expect to be able to do in their default browser with web apps other than SharePoint. After you select an external link in the SharePoint app, there is an option to open it in a browser, but users get the error message first. So they may not realize they can open it in a browser and have it work correctly. Another option would be to have a setting for each hyperlink throughout O365 to force opening in a new window or to open in the same window. Even if you left the default behavior as it is currently, it would at least give content editors the option to force one or the other to resolve the issues which result in external links being opened in the SharePoint mobile app. Without this change, we're stuck with promoting the web-only version of our SharePoint Online site to our employees instead of using the SharePoint mobile app.

Thanks for your consideration