Readlang allow text to be easily imported from websites (via extension for Chrome or Firefox) or e-books. Then you can select words of phrases for translation and these are automatically stored in wordlists (with a speak option) and flashcards - with spaced learning. The huge plus for me is the ability to...
ProAble to sync text with Youtube videos to teach correct pronunciation
ProStrips off the unnecessary text
ProYou can import long texts, including whole books
ProCreates flashcards from words you don't know
ProTranslates native content quickly