Flickr, the ever-more-popular photo-sharing service, has a five-year history of apps built on its API. From the interesting to the useful to the pretty to the downright silly, these applications make up a colorful and varied ecosystem around the service itself.

Flickr has organized these third-party apps into a "garden," complete with user favorites, tags, descriptions and screenshots. The App Garden represents a significant evolution from the former "services" section on the user side, and the revamp includes new features for developers, who can now use the Garden as a tool to help users discover their products. Read on for details and a few spotlighted Flickr apps we thought were fun.

As Flickr software engineer Mikhail Pachenko wrote on the Flickr developer blog, "We've tried to make things as simple and straight-forward as possible" for developers. On a new Apps By Me page, devs will find their apps are kept private until the creator decides to go public with the product.

"When you click on one of your apps," Pachenko continued, "you will be taken to the owner view of your app page. This page is where you tell the world about your app - provide a description, link to a website, set screenshots, and add tags. When you're ready, change the privacy setting to public. That will make your app visible to other users and allow it to show up in searches."

Now, for end users, here are a few apps we picked from the Garden that we think you might like.

Bubblr Makes Comics

Make comic strips from your or others' Flickr photos with this fun, simple application from Barcelona-based shop Pimpampum. The app allows users to search for photos by user or by tag, string the pics into strips, and add captions, thought bubbles and speech bubbles. Creations can be shared via a user's blog, Delicious or email.

Flickr For Busy People Speeds Up Skimming

This delightful time-saver shows a compact grid of photos uploaded from a user's contacts during given time periods between 30 minutes and 8 hours prior to the current time. Below each user's avatar is the number of photos uploaded, and the avatars can be clicked to display (or hide) an array of thumbnails to quick digestion of the day's pics.

Suggestify Geotags Photos

This app lets users geotag other users' Flickr photos by suggesting a location to the photo's owner. That geotag information is stored with Suggestify until the photo owner approves or rejects the suggestion. If approved, the photo is geotagged and the user who suggested the geotag is credited with a special tag on the photo.

Flogr Turns Flickr Pics Into Photo Blogs

Flogr is a PHP/MySQL-powered photoblog interface that displays a main photo page with EXIF data and Flickr comments, a customizable thumbnails page of a user's recent pictures, a slideshow component, a tag cloud and an about page showing the Flickr user's profile. Users can also determine which photos are displayed by telling Flogr to only include images with certain tags.

Flickriver Surfaces Interesting Photos

This app is focused on delivering a seamless, quick viewing experience with minimal visual distraction. Users can choose to check out interesting photos filtered by user or by group. They can search for photos or simply browse to discover the most interesting photos on a given day. Flickriver also includes a keyboard-operated slideshow mode. Better still, Flickriver offers a dynamic badge for bloggers to showcase their images.