I think Padlet is a very versatile tool and I have used it on many occasions and for a variety of tasks, e.g. posting handouts with activities such as gapfill, open-ended/closed questions, posting audio files. Students could practise skills such as listening, reading, writing, as well as grammar and vocabulary. They can be asked to do the tasks individually or in pairs/groups. It’s easy to post feedback and comment on each other’s contributions.
I think Padlet can be used effectively for both homework and during the class. Posting students homework on the padlet and then asking them to upload their answers is something that works well. I’ve used it for reading, writing, listening and even speaking tasks (students had to record themselves). With regards to using padlet during the class, it’s really handy to upload audio files/handouts there. Students get used to it very quickly. It’s also really easy to see who is actively participating in the class. It simply becomes a virtual whiteboard that is much better that an actual one because many people can use it at the same time.