With this floater, wich will stay open even if you close SBM Utilities, you can watch the heap utilisation.
The upper number shows the amount of free heap in byte.
The other number can be used for determining the amount of heap the creation of an object will occupy. To do this, tap the "R" button (Reset) and the number will set to 0 (there is a little deviation possible). Now execute the desired operation (open an application, a view, create an object, ...) an watch the difference. The number will report the bytes occupied by the operation. If the number is less then zero, the operation has freed some heap.