At the moment, no one is looking into Aptos ecosystem , I believe there are some good airdrop opportunities once $APT starts going up north high is inevitable as there will be a solana killer narrative.
Amnis finance - LST protocol, it has an ongoing campaign, just stake some $APT, I staked 50 $APT and it shows my rank as 1323, we are so early
Aries markets - liquidity market, borrow, lend and swap some tokens
Baptswap - AMM, do some swaps
Pontem Network - wallet and AMM, install wallet extension, do some swaps