HSHTG - Generate, manage, save and edit hashtags just in a few finger tap
Hashtagify.me - Free hashtags search engine, with paid advanced analytics
RiteBoost - Auto-hashtags, Auto-emojis, GIFs and much, much more, all according to your Enahce rules.
HashtagWiki.com - Hashtag Generator Tool
TrackMyHashtag - TrackMyHashtag is a Social Media Analytics tool which focuses on social media campaigns data tracking, collecting and analysing. TrackMyHashtag is currently serving in Twitter domain and possesses one of the biggest repository of Twitter data.
Twitonomy - Twitter analytics and much more.