Tweet Deck for PC has a global filter that allows this but I cannot see this option in the Android client.
As above, is there an app that has this feature?
I would very much like to clear my tweetstream of Foursquare noise and the like.
Touiteur has been updated today and now has filtering. Please note that this feature may just be the paid version. I'll update this answer with a link and QR code when I've confirmed those details.
Edit: It would seem that filtering isn't a premium feature.
The filtering can be found under the mute settings in Touiteur -> More -> Mute. You can choose to mute text (inc. hashtags), users and apps (sources).