The software development kit was released recently to developers. Im sure it will take some time for apps to be developed. We would also need some sort of software update in order for them to have a gateway for browsing / buying / and installing new apps. Similar to that of the App Store with apple and the Android Market for Android phones.
For now im pretty sure all google web apps work. you could use their online calendar. that way you can access your calendar from any computer.
Where are the new APPs and how do you install them.? For example a Planner APP or at least a calendar APP. Are any apps available in addition to the EXTRAs that come pre-installed in the NOOKCOLOR?
Not currently...no, there are no apps available. "Soon" (as in sometime during the 1st quarter of 2011) Barnes and Noble should have an app store up and running. It will carry apps that have been developed for the NC and have been "approved" by the developer's program folks.
That is perfectly NORMAL. The apps must fit in line with what the NC is (an eReader first) and must NOT harm it's basic function nor be subject to "hacking" or other harmful activities.
So you may not see an app that allows you to use your NC as a level, but you might well see an app that allows the NC to act as a notepad.
NOTE... I have ZERO affiliation with Barnes and Noble and have NO "inside" information, I am basing the above on publically avaialble information about the Nook Developer's program.