Grammar Snacks is a great site from the British Council to watch videos about grammar shown in a natural way.
The videos offer the grammar in context with subtitles and although the videos might be a bit too long for an elementary student , it gives them the chance to read along and improve pronunciation. So, as the idiom goes, you kill two birds ( or maybe three) with the same stone. After watching the video there’s a clear grammatical explanation about when and how the grammar is used and some attractive interactive exercises.
So far, the site offers videos on the following :
♥Comparatives and Superlatives
♥There is/are and It
♥This, these , that, those
♥The Present Continuous
♥The past Simple: regular and irregular verbs
♥To Be: Present and Past
♥Countable and Uncountable