As far as launchpads go, two things come to mind. Like you said, OGLONG is one of the leading launchpads in the bitcoin chain, and also the first community-owned launchpad designed specifically for Runes.
Asides this, exchanges like the ones you mentioned also offer launchpads for some projects. These are just events that allow users to get new tokens. It's similar to the PoolX that Bitget currently has for OGLONG where you can stake some BTC to get the token.
