DotDotGoose
DotDotGoose is a free, open source tool to assist with manually counting objects in images. DotDotGoose was purpose-built since most conservation researchers and practitioners working on counting objects in images were using popular software which are not ideally suited for many conservation applications.
The DotDotGoose interface makes it easy to create and edit classes of objects to be counted and you can pan and zoom to accurately place points to label individual objects. Information about objects can be stored in custom fields and this metadata can be exported for use in spreadsheet or statistics software.
Point data collected with DotDotGoose will be very valuable validation data for any future efforts with computer-assisted counting.