There have been questions around the reservation system and Apps, here is some additional thinking from the Board and myself.
We are putting the reservation system in place for several reasons. First is for health and safety. Today we don't know who stayed where, and occasionally there is an issue when we need to know if someone stayed somewhere, and for that reason we would like to have a record if possible. Second, today we don't know who is using the system where and when. This makes improving the system very difficult. Having some information about use patterns. would be very helpful. Finally, and perhaps most importantly, without knowing that someone stayed somewhere, we can't ask them for a review of the host/guest and vice versa. Reviews are the lifeblood of warmshowers.org, that one-on-one understanding of whether someone was a good guest/host, that allows others to make an informed choice about where they are staying, or who they are hosting. By using the reservation system, we can then follow up with guests/hosts to write a review, which benefits everyone using the system.
You will be able communicate directly with a potential host or guest if that is your choice with the new system. I think you will appreciate the ease of use, the ability to communicate as you always have, and also the added benefits the reservation systems will engender.
The apps will no longer function with the launch of the new website. We haven't heard much from the community around this change, given the new site will be responsive and therefore device agnostic, however if there is substantial demand for the apps, and the willingness to fund them, we will of course build new ones that are aligned to the new site.