There’s a large choice in the sort of tasks a teacher can hand out, which are deployable as formative as well as summative assessments. This could be a simple hand-in to teacher, but also a rubric, a questionnaire or survey, keeping records (maybe in the form of a graph) or a timeline.
All these could be individual tasks or a group task. Tasks can be assessed by teachers, students or both. This can be done verbally (text) and when wanted combined with a mark, a scale, rubric or check.