In WeChat, 撤回消息 (unsend a message) is the most common modern use. You have 2 minutes to 撤回 a sent message. Beyond that: 撤回申请 (withdraw an application), 撤回部队 (withdraw troops).
mistakes
撤回 (withdraw/retract) vs 撤退 (retreat militarily) vs 撤销 (revoke/cancel officially). 撤回 implies pulling something back; 撤销 implies nullifying it entirely.