I dont't think there is a valid direct translation for snapchat. The problem is that the word is composed from "snapshot" and "chat" an in english you easily undestand that it implies "chating with snapshots, using the app named Snapchat". In spanish, the words are traslated to "foto instantánea" and "charlar" and you can't make a portmanteau of those words. Also the app is still named Snapchat in spanish. Maybe you can join the words in something like "fotocharlar" or even "fotochatear", since that in most spanish-speaking countries many technological terms are not directly translated and we use the english term in a modified version. But "fotocharlar" doesn't imply which app will you be using. You can "fotocharlar" with any app that allows photos and chat. Maybe using the app name as a verb the infinitive would be "snapchatear"; as in: - yo snapchateo, tu snapchateas, nosotros snapchateamos, etc.. But honestly, I don't know anybody that would use the verb "snapchatear" seriously. There are many words in english that are used as verbs, but we don't use them as verb in spanish. I don't say "Te skypeo mas tarde", (I will skype you later). I only say: "Te llamo por skype mas tarde" (I will call you later through skype). In the same way, I would probably say: "Te hablo mas tarde por snapchat", meaning "I will talk with you later through snapchat"