Minor improvements and bug fixes

AutoVocab 2.0 — the biggest update yet. • A complete redesign: new look, new tab bar, smoother everything • Practice games: Quick Quiz, Reverse Quiz, Flashcards, Scramble, Fill the Blank, Match Pairs, Speed Round, and Smart Mix — built from your weakest words • Progression: XP, levels, streaks and 24 badges to earn • Word Drill: a focused round for any single word • Multiple definitions per word, each with its own part of speech and CEFR level • Add Word now searches the dictionary as you type and fills everything in • Memory strength on every word — see what's about to fade • Voice overhaul: clearer pronunciation, spoken in the word's own language • Sturdier notification scheduling and many fixes

- Home screen widgets - Improved notification scheduling algorithm - Bug fixes and performance improvements

Minor fixes