It definitely needs sync to be viable.

I'm at the laptop during the day and at the PC during the evenings. Most of my snoozes end up being for the evening. This makes "Send tab to device" more viable, except you don't control the time it pops up.

It's OK, but the "pick date and time" is primitive.

I love it but give 3 stars because it does not sync across devices.

Works as expected but quite minimalist. Needs much much more features (currently using http://www.tabsnooze.com for Chrome).
Keep the good work rolling!