Findings Electronic Lab Notebook
I just noticed that Findings have altered their pricing structure, you can now download a free version that contains all the functionality of the full version but is limited to 20 experiments.
Findings Basic is the entry point for users that have limited needs, or newcomers that just want to try things out. With Findings Basic, you can create up to 20 experiments. The entire app is otherwise fully functional, including export and sync, and you can create and edit an unlimited number of protocols.
There is a review of Findings here