It’s an easy way to stay in touch with friends you don't personally know as well! I like that there's no need of separate accounts or different apps since everything happens through one app (Groupme).
There are multiple options when it comes time deciding which color/theme looks best but they all look good so choose what works most effectively within your team dynamic while also keeping users' privacy intact from other members at risk!! Having something centralized makes things much easier too - especially if someone doesn't have access because he forgot his password etc.,etc..