I’ve been using Memrise for a year with my students and it’s working very well. Here’s what happens…
Google ‘Memrise’ and select a course from the site. Your first word is given to you in the original language and in English.
Clicking on an arrow will often give you a "mem", a mnemonic which is verbal and/or visual. There is sometimes audio so that you can practice punctuation as well. Then you get a multiple choice test of the word before you go on to another word. You are tested again on these words and the test will involve typing in the word in your own and the target langua
The particular beauty of the system is that each time you log on you are invited to revise vocabulary. But if you get the words right each time you are checked at increasingly longer intervals. If on the other hand you make mistakes the opposite is the case. However all words recur from time to time. The idea is to check up on vocabulary at the moment when the words are likely to slip from your memory.
I’ve created a lot of short courses mainly aimed at Junior Cert. Google them with "rosmucfrancais" and select one or look at adjectives, for example.
To reduce the number of words, I usually leave out words that are very similar to English. These can be quickly covered in class.
Most people will probably want to make their own courses and the site explains how to do this if you aren’t happy with our one or the others that are available.