ODK
KoBo Toolbox is a webhosted application for creating forms that can be used offline, collecting form data, visualizing and analyzing your aggregated data. It is easy to set up and deploy. It uses the same platform as ODK, and is easily interconvertible with ODK Aggregate, XLSForms, and other data collection tools, as well as with Google Geotools such as Fusion Tables, Earth and My Maps.
The form maker is much easier than ODK, and you do not have to set up an aggregation site on a server to use KoBo Toolbox. However, there are some limitations in how the photos are handled, and you cannot export directly to Fusion Tables (you must download the CSV file) - if you are doing a large project you will want to use KoBo Toolbox in conjunction with ODK Aggregate to get the most functionality (but you can do a lot very quickly with just KoBo Toolbox for smaller projects).
Download KoBo Collect from Android Play Store
Comparison of KoBo Toolbox, ODK and other tools
Case Study: Using sensors on mobile phones to collect health data