In planning meeting, scrum teem members make estimates by playing numbered cards face-down to the table, instead of speaking them aloud.
The online scrum poker app provided an online tool for scrum teem to host planning in LAN, instead of necessarily sitting together.
The app does not require a backend server to support. And anyone in the same WIFI can either host a meeting or join a established meeting as guest.
After joining the online meeting, all members can vote for the estimation number respectively without revealing the actual number to others. After all members finish voting, the host will reveal all estimation number at the same time.