Online qurans'

quran.com---has notes feature embedded in website

The Quranic Arabic Corpus

quaranx.com

sunnah.com

quranwow.com

nquran.com/ar/

Quran apps

Tarteel

Quranly

Shi'a

Imamate

Twelver Shi'ism

Sunni

Sufism

Ibadism

Ismailism

Zaydism

Schools of thought in Islam

Calligraphy