Yes sweatcoin is a digital currency but it isn't like bitcoins. You can only get sweatcoins by downloading the sweatcoin app. This is more like a workout app where you'll earn 1 sweatcoin for every 1000 steps you take doing out door activities. Now we know bitcoin doesn't work like this. It is investment and returns mostly.
When you gather enough sweatcoins, you can't exchange for cash in paypal or shop elsewhere with it like with bitcoins. With sweatcoins you can only exchange them within the app. They have certain retailers like sports, Amazon,gifts etc. They don't have a cash reward system just yet.
Bitcoin is a cryptocurrency and in my opinion, it is definitely more advantageous than sweatcoin. You can always exchange it for Fiat currency. It is a universal currency since anyone from anywhere can use it. Sweatcoin whereas is limited. They don't even compare.