Image Resizer vBulletin Style
Resizes large images within posts so that they don't break your layout.

TinyPic Plugin
Adds a TinyPic upload button to the posting editor.

Extended Template (Categories Hierarchy Add-on)
Replacement of the phpBB template parser, based on the phpBB Olympus one. It handles cached .tpls and is faster than the regular parser.

Topic Calendar (Categories Hierarchy Add-on)
Calendar that allows you to use topics as events with a dedicated date.

Post Icons
This hack will add icons in front of the title of topics.

Split Topic Type
This hack allows you to have the global announcement, announcement and sticky topic split from the standard topics in viewforum.

Announcement Suite
Displays announcements on index and/or above forums of the same category according to the user's permissions. Permissions based.

Categories Hierarchy (Sub Forums)
This hack allows you to have sub forums and sub categories on your phpBB and also gives you the ability to add forum links (links displayed as forums).

Japanese Language Pack for phpBB Auction
Japanese language pack for phpBB Auction.

derefer.me Hack
Makes it so that all user posted external hyperlinks, with or without URL BBcode tags, are through an external link redirection service, in order to mask the referrer.

Posting Template
Let's the admin specify a posting template on per forum basis.

Multiple File Uploads
Allows users (all who can upload) to upload more then one file at a time in the upload form.

TruBar
Uses a text based captcha for guest posters, so that they have to enter the code before their post goes through.

Smilie Hide Hack
Allows administrators to hide specific smilie icons from the selection area in posts and PMs. The smilie can still be used by typing the smilie code directly in the post or PM.

Group Members by Character
Adds a line of characters on top of the memberlist when viewing the group members.

View Banlist Content
Shows the content from the banlist table and includes a delete link after each row, allowing you to remove bans that are currently in place.

UploadPic
Allows users to add an image link through the posting box and then the picture will be uploaded and displayed in the topic.

Admin Panel for Junior Admins and Mods
Allows you to define restricted access for junior admins and moderators to your admin control panel.

Sudoku
Version of the popular numbers puzzle that can be played on your phpBB.

Social Bookmarking Buttons
Adds in each thread a series of buttons for all of the major social bookmarking sites including Digg, Reddit, Furl and others.