I just shared a simple (probably the simplest) block called "Echo", which may partially solve your problem.
1. If you want to display all info of a block output, Popfly can do so if the output object has a toString() method.
2. If you want to display only one field of a block output, you can connect the block to "Echo", and tell Echo to echo one field.
3. If your want to make changes to the output, you may need to (a) write a block; (b) change the JavaScript directly in mashup editor (block configuration --> advanced view).