Cheogram is based on XMPP, and as such federated XMPP users can take advantage of some unique features.
Cheogram is actually a proxy layer on top of simpler XMPP SMS gateways. As such, there is an ad-hoc command available to let you use any federated gateway you want, instead of paying for our default route.
Why would you do that? Cheogram adds features your gateway may not support, and provides stable JIDs that don't change even if you port your number to a different provider or switch gateways.
Some known backend routes include:
Cheogram supports the XEP-0100 jabber:iq:gateway protocol. If you add cheogram.com to your roster, clients such as Gajim and Movim will enable special UI to add an "sms" contact. Enter the phone number, and the correct JID will be generated for you automatically.
Cheogram adds XEP-0184 on top of gateways that don't support it, so you can easily see if your message has made it to the SMS network, even when your internet is unreliable.
Cheogram supports XEP-0115 that includes any advertised discovery information from the underlying gateway, so all your gateway's abilities can be cached by clients and reduce bandwidth (especially useful on mobile networks).
Cheogram automatically verifies the relationship between your JID and phone numbers you route through it, and allows other XMPP users who know your phone number to discover your JID so you can message each other directly and save on SMS fees.
Cheogram replies to XEP-0199 ping requests on itself and all proxied JIDs.
Cheogram includes an early prototype of multi-user chat functionality. Simply invite any of your Cheogram contacts to a MUC and they will receive an SMS allowing them to join the conversation.