Favorite language things
Online dictionaries and translators
Linguee -- multiple bilingual German-based dictionaries
DeepL -- an instantaneous translator that often beats Google Translator
DWDS (Digitales Wortbuch der deutschen Sprache) -- excellent for finding practical use cases for new words; I regularly used the Korpusbelege to make Anki flashcards when preparing for a C1 exam
Wordreference -- numerous bilingual dictionaries
Glosbe -- one of the few decent bilingual dictionaries that also accounts for Bulgarian
PONS -- multiple bilingual German-based dictionaries; I've also used PONS books to build a basis in Bulgarian
Dict.cc -- multiple bilingual German-based dictionaries; absolutely essential for data-free travel
WIPO Translate -- another deep-learning-based translation tool, trained specifically on patents
Language-learning software and resources
Spaced repetition and flashcards
Anki -- space-repetition flashcard software that has revolutionized the way I learn languages. The learning curve is steep-- you should be comfortable editing TeX, HTML, and CSS if you want to edit flashcard templates-- but even the basic templates are quite powerful. I've developed my own decks for Bulgarian and German.
Rosetta Stone -- great software for getting a solid foundation in a new language without using your native language as a crutch; expensive (but also easy to get for 90% off if you sign up for their newsletter). A lot of people hate it, but it gave me a solid foundation in German.
Memrise -- a simple app for picking up new vocabulary via spaced repetition; most useful decks are user-created and may have errors, but overall this has been a great supplement to my language-learning journey, especially the browser version. (Also, completely free.)
Transparent Language -- simple software for learning less "trendy" languages, like Bulgarian and Czech. Unfortunately, both courses I tried were absolutely riddled with errors and taught weird, often useless phrases... hence why I decided to make my own BG curriculum via Anki.
Online exercises with immediate feedback:
Lingolia -- detailed grammatical explanations and practice worksheets with immediate feedback
Podcasts and audio training:
Beelingueapp -- a lovely app for reading simple texts in two languages at once
Français Authentique -- great podcasts for learning French on-the-go
EasyGerman -- cute videos with subtitles and interviews with people on the street
Radio Ambulante -- beautifully told stories from Latin America
Catástrofe Ultravioleta -- quirky science stories; think Spanish Radiolab