I'm looking for a wall outlet adapter converting two outlets to six, like this GE one. However, for reasons I don't comprehend, that adapter (and all its clones) have only one active plug, the other being a plastic dummy. Adapters that plug into both outlets do exist (example) but the outlets they provide are too closely spaced for most wart transformers.
The reason for the one active plug is because the one you show is rated 15A which is what that configuration will carry so there is no reason to have two. On your other question you might look at the ones that have USB ports and outlets. The ports wouldn't require a transformer. last resort would be an old fashion ugly three way or cross adapter.