The short version — check out Google Keep, Quizlet, GoVocab, and Lang-8 for your foreign language classroom.
Google Keep
When I was last in a foreign language classroom as a student I remember taking notebooks full of notes, dating each one, and going through the notebooks later to review.
There is research that says taking notes by hand helps you remember the material better than typing, but taking notes exclusively by hand is probably not the most efficient way to study a foreign language.
Using Google Keep, students can keep organized by color-coding notes, tagging notes, and exporting them to Google Docs. In addition, like other Google products, Keep is collaborative and notes can be shared.
Quizlet
Quizlet is a great formative assessment tool, and can be a nice addition to a foreign language classroom.
Not only does it have a flashcard tool that you can add pictures to, but you can add audio to the vocabulary words, essential for correct pronunciation. For in-class use, Quizlet has several games students can play.
GoVocab
As the name states, GoVocab is an app for learning vocabulary. I tried it out and my dashboard had links to a quiz and to a spelling test. There are games, a dictionary, and pronunciation practice as well.
GoVocab was suggested by our IB Spanish teacher, Yenidil Toribio, who said that after using GoVocab in her classroom, she saw students improve.
Lang-8
Lang-8 is a site that I used in the past, and should use more while learning Chinese. Lang-8 is a social site where you can keep a journal in the language you are learning.
Each time you write a post, native speakers will make corrections for you. There are sometimes many different ways of saying things, so feedback can be different depending on who you get it from.
Since the posts are saved on the site, Lang-8 can be a great way to track student writing progress over time.
HiNative, the iOS app by Lang-8 for asking questions to native speakers