>> Rorohiko (aka Lightning Brain) has a number of cool plug-ins for InDesign users. For example, FrameReporter ($29 US) lets you see small informational tags when you click on a frame, such as the image's effective resolution or how many words are overset. You can even use it to name frames, and then navigate around your layout via the names. Special for InDesignSecrets listeners: Use the coupon code INDESIGNSECRETS111 (that's "one one one" at the end) in the Rorohiko.com store to get 25% off the FrameReporter plug-in.
>> In-Tools has a very cool plug-in called AutoFlow Pro. It lets you set autoflow attributes for individual stories within your layout, letting you fully control which stories will automatically generate new threaded frames and pages as you enter text, and which ones simply overset. The plug-in is $99, but InDesignSecrets fans can get $20 off the price for either one of their InDesign plug-in bundles, InBook or InSefer, (both of which include AutoFlow Pro) if you purchase from this special page on their site. The full list of plug-ins bundled in the packages is here.