Joshua Parker

If you are running a WPMS (Multisite) blogging network, the issue with most login widgets that you add to the main site’s sidebar is that it doesn’t pull the user’s own blog info. That is why the WPMS Sidebar Login Widget was created. Instead of the user trying to remember the login page of their own site/blog, when a user logs into your main site, the widget will conveniently contain links to navigate to 3 different pages of the user’s blog: dashboard, new post page, and profile page.
Features:
<ul>
<li>Link to Network Admin page (only shows if user logged in is a super admin)</li>
<li>Link to user’s dashboard</li>
<li>Link to user’s new post page</li>
<li>Link to user’s profile page</li>
<li>Link to forums page</li>
<li>Subblog registration detection</li>
<li>Custom CSS settings</li>
</ul>
To make sure it works, activate the <a href="https://wordpress.org/extend/plugins/user-switching/" rel="ugc">User Switching</a> plugin on the main site only to switch to a different user.

WPMS Sidebar Login Widget

Adds a sidebar widget to the main site of a WPMU/WPMS install.

lenasterg

BP Group Documents creates a page within each BuddyPress group to upload and any type of file or document. This allows members of BuddyPress groups to upload and store files and documents that are relevant to the group.
Documents can be edited and deleted either by the document owner or by the group administrator. 
Categories can be used to organize documents. 
Activity is logged in the main activity stream, and is also tied to the user and group activity streams. 
The site administrator can set filters on file extensions, set display options. 
Group members and moderators can receive email notifications at their option. 
The group administrator can decide if all members or only admins/moderators can upload documents (Since v0.5) 
User verification for Downloads: when a document is downloaded, a redirect page checks is the user is member of the group (in case of a private or hidden groups) and only then the user can download the file.(Since v0.5) 
For private networks, see the FAQ “I have a members only network. How to disable file download for non members?” .
4 Widgets: “User’s groups documents”, “Recent Uploads” , “Popular Downloads”, can be used to show activity at a glance. If the theme support different sidebars for group pages, the BP_Group_Documents_CurrentGroup_Widget can be used to show current group’s documents.
Contributions by Lena Stergatou, with additional bug fixes and improvements by Keeble Smith (http://keeblesmith.com) and Anton Andreasson work for BP 1.7.
Original plugin author was Peter Anselmo.
PLEASE: If you have any issues or it doesn’t work for you, please report in support forum. It doesn’t help anyone to mark “broken” without asking around. Thanks!
<h3>Notes</h3>
Roadmap.txt – contains ideas proposed and the (approximate) order of implementation
History.txt – contains all the changes since version .1
License.txt – contains the licensing details for this component.

BP Group Documents

Great functionality, and good notifications!

This is the plugin every buddypress user should have

BP Group Documents creates a page within each BuddyPress group to upload and any type of file or document.

WPMS Sidebar Login Widget vs BP Group Documents