After spending six months wrestling with French verb conjugations, I can tell you which resources made the difference between constant confusion and gradual understanding. These are the tools I use weekly, not just apps I downloaded and forgot about.
The reference book that stays open on my desk
Bescherelle La Conjugaison pour tous sits next to my keyboard because it shows every verb form without the motivational fluff. When I need to know whether a verb takes être or avoir in passé composé, this book gives me the answer in under thirty seconds. The index alone saved me hours of searching online forums.
Why I still use Lawless French despite its dated design
Laura Lawless built a grammar index that covers specific questions like when to use y versus en. The site looks like it is from 2008, but the explanations include examples that show context, not just isolated rules. I check it three times per week when doing exercises.
The mobile app for drill practice
Conjugaison Française handles verb drilling without turning it into a game. You pick a tense, conjugate twenty verbs, see your mistakes. The feedback is immediate and specific about which ending you got wrong.
These three resources cost me less than one tutoring session and cover the repetitive lookup work that used to interrupt my reading practice every few minutes.