I haven't seen too many apps worth $.99 let alone $6, but tasker is unbelievable. Tasker's automation features really take your phone to the next level. Lifehacker did a great review:
How to Turn Your Android Phone into a Fully-Automated Superphone
Stuff I love:
Turn speaker phone on automatically when the phone is placed flat on its back.
Turn GPS on when foursquare or navigation is loaded, and GPS back off when they are closed, all automatically.
Phone goes on silent mode automatically when I place the phone flat on its front.
How to Turn Your Android Phone into a Fully-Automated Superphone
Stuff I love:
Turn speaker phone on automatically when the phone is placed flat on its back.
Turn GPS on when foursquare or navigation is loaded, and GPS back off when they are closed, all automatically.
Phone goes on silent mode automatically when I place the phone flat on its front.