After experimenting with Planboard I thought it was a tool which was very easy to use. It is set up much like the traditional paper plan book, but provides the benefits of being paperless and easily accessible from anywhere with an internet connection. For this reason I could see it being incredibly useful in the case of substitute teachers so they could have access to the teachers plan even though the teacher may not have expected to be absent on the given day. Along with the lesson plan itself it is also possible to attach documents to any given lesson.
Another feature worth noting about Planboard is their standards tool. This tool allows the teacher to type in keywords of what they are looking for and pulls up the relevant standards. Additionally, Planboard allows for easy exporting of material including saving as a pdf, emailing, and printing the material. My one concern about this app is that it is only free for up to 500mb of space. Once that space is filled they recommend upgrading to a pro account which costs $30 for a year. This makes me curious to see what else is out there in terms of online lesson planning.