At the Bitcoin Conference today in Miami, Robinhood announced they will soon add Bitcoin Lightning Payments into the Robinhood mobile app.
Lightning is a layer-2 technology network that uses Bitcoin in time lock contracts, it's similar to opening a bar tab but there is a guarantee that the tab can be paid since its backed by a Bitcoin contract.
Litecoin also has a lightning network, currently it is not needed as on-chain fees and capacity of the litecoin blockchain don't require layer-2 technologies just yet. However, the network is available and can be used today.
The first lightning transactions was actually done on Litecoin before Bitcoin.