Here are my favorite new features of FileMaker 13...
The Field Picker
The new Field Picker tool makes it very easy to add fields to a layout. You can add multiple fields at one time, and even indicate how those fields should be positioned relative to one another (vertically or horizontally). You can also choose whether or not to add field labels, and if so, whether they should appear beside or above the fields.
In addition, the Field Picker provides a convenient way to add new fields to a table without the need to open the Manage Database dialog. And for those of you with tables that have a large number of fields, you'll be happy to hear that you can use the Field Picker to search for fields - and change the sort order of the fields - so finding a field will be much easier. You can even right-click on a field to access a field's options, or to delete a field.
New Layout Objects
FileMaker 13 includes support for two new layout objects: slide controls and popovers.
A slide control is like a tab control, in that it lets you setup areas of a layout whose content can change on the fly. With slide controls, you can setup multiple panels that slide to reveal different content.
We've seen popovers in iOS-based apps for quite some time now. They're similar to popup windows, except that they're actually anchored to an object on a layout and aren't really new windows at all. Instead, they reveal additional content in an area that essentially floats above the layout itself. And because they aren't really new windows, they're fully supported by the new version of FileMaker Go.
Hide Layout Objects
Remember all of those hacks that you used to use in order to hide objects on a layout? Well, you don't need those anymore. The new "Hide object when" layout object option (which is available under the Inspector's Data tab / Behavior section), gives you the ability to truly hide a layout object based on a calculation.
Enhancements to the ExecuteSQL Function
The ExecuteSQL function has been enhanced so that you can specify a starting row ("offest") and the maximum number of rows to be returned ("fetch"). For example: ExecuteSQL ( "SELECT Last_Name, First_Name FROM Contacts ORDER BY Last_Name, First_Name OFFSET 1000 ROWS FETCH FIRST 25 ROWS ONLY"; "|"; ¶ )
Perform Script on Server
With this new script step, you can indicate that a script (in a hosted database) should be run on the server itself - thus maximizing performance. You can even indicate whether or not the client should wait for the result of the script. This is ideal for data-intensive scripts.
HTTP Post Support
I think this is my favorite new feature of 13. You can now use the Insert from URL script step with httppost and httpspost protocols. I'm looking forwarding to using this to more seamlessly integrate FileMaker with Web services.