While we’re necroposting
Other posters have mentioned Yomiwa and Imiwa? as dictionaries. I personally prefer Midori (App Store) for its interface and design—I find it quicker to use if I need to find a word when reading. Features are similar to the other dictionary apps (but no OCR).
Seconding (thirding?) JLPT test N1-N5 - Migii (App Store) and Easy Japanese News やさしい日本語ニュース (App Store) for free practice JLPT tests. There are some mistakes/issues with each, but nothing horrendous. I’m considering buying a short-term subscription for only when I want additional practice tests (there are constantly sales…).
I’ve been using StickyStudy Japanese (App Store) as my main tool for kanji and vocabulary SRS for years. Not free ($10 USD and no in-app purchases) though I found it well worth the price. It has built-in decks for Joyo (old+new)/school grade/JLPT kanji and vocab (by JLPT level) and you can create your own decks as well. The test setup (audio, kana, kanji, english) and the SRS times are completely customizable. Best with (your favourite) kanji dictionary, so YMMV.
I’ve also checked out Bunpo (different from Bunpro!), but I found that the lessons and reviews were a bit underdeveloped.