Inscovery - Discover unique Instagram users that share your interests
HSHTG - Generate, manage, save and edit hashtags just in a few finger tap
Roundio - Explore what people posted to Instagram or Flickr near you
hashtags.org - Hashtag is an extensive hashtag research platform for analytics and tracking of hashtags, providing...
Instaround - A simple app to find Instagram photos and people around you.
HashtagWiki.com - Hashtag Generator Tool