Hi, you should take a look at MemoLeaf from Redwood-Creative.com. It will allow you to create a project memo, list next actions and their context in the body of the memo, and then search on context tag and see all the activities for a particular contetxt in a list, so you know what needs to be done.
Build Cat House
@errands: buy wood and nails
@calls: order design from pet store
@home: build cathouse in backyard
You can then search for @calls and you will get a list of all lines with @Calls in the body. If you want to use Memo for projects, it works great. Just put a space in between or eliminate the @ sign for any context actions you don't want to have show up yet.
As for InBox, it allows you to use your Memo app as a capture tool and then dump your notes into any of the four basic apps.