It seems the service has shut down in August 2020.
Far too weird and clunky
Pluses: The interface is similar to Garageband. You can make music in 15 minutes, once you create a free account. Everything is done online.Minuses: Their loops are all disorganised, there are hundreds and are not sorted in any obvious way. You have to listen to each one in order to find ones that match the key of your song (in the tutorial it says the loops are all selected to match the key, but that is not true) . All your creations become licensed to Looplabs, and you may only use your music for personal, non-commercial use. The only way to download your song is by making it public on their site. Also, all the loops are the same duration.
Our users have written 2 comments and reviews about Looplabs, and it has gotten 15 likes