Here's the English translation of your app description, optimized for the Google Play Store with keywords in mind.

One-Line Diary - Your Simple & Free Daily Journal App
"Want an easy-to-keep diary?" "Looking to build a habit of daily recording?" "Searching for a simple and user-friendly memo app?"

One-Line Diary is the perfect app for you.

Even on busy days, just write one line! No pressure, no stress. You can easily make journaling a daily habit. Even if you find writing difficult or tend to give up quickly, this simple, free app helps you continue effortlessly.

Who is One-Line Diary for?
・Those who want to keep a diary but struggle to stick with it.
・Anyone seeking a simple design and intuitive diary app.
・Minimalists who prefer recording apps with just the right amount of features.
・Individuals wanting to easily keep a life log of their daily records.
・People looking for a quick way to record their daily routines like a planner or notebook.
・Those aiming to boost self-esteem through positive reflection.

What You Can Do with One-Line Diary
Easy 1-Line Entry: Jot down daily events, feelings, or things you're grateful for — just one line is all it takes.
Habit Support: Writing daily naturally builds a journaling habit. Continuing your life log enriches your life.
Reflection Feature: Easily view past diary entries and records. Recall those moments and boost your self-esteem.
Simple & Beautiful Design: A minimalist, refined UI free from unnecessary clutter, providing an environment where you can focus on writing.
Completely Free: Enjoy all features without any additional costs.
One-Line Diary makes journaling easier and more accessible. You don't need to carry a planner or notebook; your smartphone is all you need to build up your records.

Why not start your gentle one-line habit today? We hope your everyday life becomes richer with One-Line Diary.