I recommend...

Grammar web pages:

Englisch Hilfen

The Perfect Grammar

All ThingsGrammar

English Exercises (you need to register)

English Grammar on line

On You Tube:

Learn English with Let's Talk - Free English lessons

https://www.youtube.com/user/ShawEducation

https://www.youtube.com/user/oxfordonlineenglish

News in English:

CNN Student News

If you like singing:

Lyricstraining.com

English culture:

Short Video documentaries about Britain and the USA

Free Podcasts and video lessons:

TED-Ed lessons

Listen to English - Learn English!

Randall's ESL cyber listening lab

PDF with more listening resources

ESL video quizes

Learn with short film videoclips ( www.learnenglishfeelgood.com)

Clark and Miller

English Listening Lessons Library

Audio English . org

Useful phrases & Vocabulary lists:

Speak English!

All Things Topics

General:

Learn English Teens

Learn English Kids

Agenda web (english on line exercises and printables)

Aprende mas inglés (Learn English pronunciation, grammar, vocabulary... from an American Teacher who lives in Madrid)

Aprende inglés con Sila (Just the other way round, a Spanish teacher's web who has lived in London)

Tests

Free online tests

My English level.

Cambridge Exams preparation

Test Your English (listenings, grammar, writing tests...)

For teachers...

busyteacher.com

https://en.islcollective.com/

https://www.teach-this.com/

TeachEnglish, British Council: https://www.teachingenglish.org.uk

https://justificaturespuesta.com/

CLIL:

https://www.pinterest.es/mrosasalo/clil/

BBC bitesize

https://www.schoolingamonkey.com/science-experiments-for-kids/

https://www.worldofchemicals.com/455/chemistry-articles/chemistry-in-everyday-life.html

https://kids.nationalgeographic.com/

Other webs i recommend...

Project Based Learning - Edutopia

Technology Based Learning - Edutopia

Educational Technology and Mobile Learning

Google 4 teachers

I Pad resources