The standard Israeli ulpan textbook — two volumes taking you A1 to about B2.
About this tool →Details
Chayat, Israeli and Kobliner's two-part course is what Israeli universities and most ulpanim actually teach from: graded texts, systematic verb-pattern tables, and exercises that build reading and writing rather than tourist phrases. Work through both volumes and you have a real foundation, which no app in this list will give you. It is almost entirely in Hebrew with minimal English support, assumes a teacher will explain things, and the audio and answer keys are sold as separate items — self-studying it is possible but hard, and buying it outside Israel means going through Judaica booksellers.