HashFlash

HashFlash is an automated social media search engine.   It allows you to quickly add/remove keyword topics you wish to monitor across all public items on Twitter, Google Plus, and Facebook.

No need to "follow" or "like" specific people or topics, all public posts are searched for your keywords and the most recent relevant results from the various feeds are listed for your review.

HashFlash is configurable for result depth as well as search frequency allowing you to customize how often you're updated.

HashFlash is available as a free trial from http://www.hashflashapp.com/trial/hashflash.apk (you will need to allow installation of unknown programs on your device). The free trial is not limited in any way, however, you will be subjected to a start-up delay until you purchase the paid app.