Can anyone tell me the purpose of locking your sats here?

To signal importance of posts, rather than likes.

Hello peeps

yup! you'll be able to sort by lock amount in search results and on the main stream soon too (next week most likely)

Good

Do you get rewarded bsv for likes like other apps.

no, locking returns bsv back to the person who locked... we will have the ability to upvalue (tip) messages in the future