The Bosch Platinum +2 and +4 an example of this isn't it?
That is correct - any spark plug that has multiple ground electrodes.
Also I have heard of people having problems with using these plugs in more higher tech engines. Is this true?
Multi-ground plugs should not be used in engines that are not designed specifically for them. If used in other engines, they will not improve performance, and may run worse than the standard recommended spark plug.
I have also heard they use more fuel than normal plugs.
I'm not sure on that one