Elhuyar Hiztegiak is a must-use app for studying Basque, no matter which language you’re learning from. It contains two-way Basque-English, Basque-Spanish, and Basque-French dictionaries. Each entry has example sentences as well as brief grammatical notes, related phrases, and expressions. It also has audio recordings for many entries.
When searching in Basque, make sure to leave off the “a” suffix unless it’s an “organic a,” i.e. part of the noun itself. So, if you wanted to know the meaning of esnea, you’d search “esne” because the “a” in this word represents “the”. However, “animalia” needs the final “a”. Thankfully, a drop-down list of words appears as you type, so there’s not too much guessing involved.
The app is fairly comprehensive, but you might struggle to find some words, especially if you’re searching in English. Before assuming the app doesn’t contain a word, however, double-check that you’ve set it to the right language – it’s a surprisingly easy mistake to make.