sources.txt

Icons used in New Game Custom Dialog (Under res/common/drawable)
    ic_easy.png, ic_intermediate.png, ic_expert.png, ic_custom.gif, ic_custom_error.png :
        Grid icons created by Freepik - Flaticon (https://www.flaticon.com/free-icons/grid)
    ic_jumbo.png :
        Menu icons created by Kiranshastry - Flaticon (https://www.flaticon.com/free-icons/menu)

Icons used in Settings and Statistics Page (Under res/common/drawable)
    setting_sound.png :
        Sound icons created by alkhalifi design - Flaticon (https://www.flaticon.com/free-icons/sound)
    games_started.png :
        Pixel icons created by Freepik - Flaticon (https://www.flaticon.com/free-icons/pixel)
        Bomb icons created by inipagistudio - Flaticon (https://www.flaticon.com/free-icons/bomb)
    games_won.png :
        Crown icons created by feen - Flaticon (https://www.flaticon.com/free-icons/crown)
    win_rate.png :
        Flag icons created by vectorsmarket15 - Flaticon (https://www.flaticon.com/free-icons/flag)
    best_time.png :
        Time icons created by Freepik - Flaticon (https://www.flaticon.com/free-icons/time)
    time.png :
        Clock icons created by dmitri13 - Flaticon (https://www.flaticon.com/free-icons/clock)
    best_win_streak.png :
        Double arrow icons created by IconKanan - Flaticon (https://www.flaticon.com/free-icons/double-arrow)
    win_streak.png :
        Right icons created by Freepik - Flaticon (https://www.flaticon.com/free-icons/right)
    wins_no_hint.png :
        Flag icons created by vectorsmarket15 - Flaticon (https://www.flaticon.com/free-icons/flag)
        Turned off icons created by Rakib Hassan Rahim - Flaticon (https://www.flaticon.com/free-icons/turned-off)

Icons used in Level Info Page (Under res/common/drawable)
    board.png :
        Pixel icons created by Freepik - Flaticon (https://www.flaticon.com/free-icons/pixel)
    mine_bomb.png :
        Mine icons created by bqlqn - Flaticon (https://www.flaticon.com/free-icons/mine)
    percentage.png :
        Load icons created by Freepik - Flaticon (https://www.flaticon.com/free-icons/load)

Minesweeper Cells (Under res/common/drawable)
    mine.png, mine_0.png ~ mine_8.png, covered.png, flagged.png :
        https://github.com/pardahlman/minesweeper/tree/master/Images
    mine_explode.png :
        https://www.pngwing.com/en/free-png-vxhwi

Navigation Bar Icons (Under res/common/drawable)
    nav_home.png :
        Home button icons created by Freepik - Flaticon (https://www.flaticon.com/free-icons/home-button)
    nav_history.png :
        Pending icons created by Freepik - Flaticon (https://www.flaticon.com/free-icons/pending)
    nav_statistics.png :
        Bar graph icons created by Freepik - Flaticon (https://www.flaticon.com/free-icons/bar-graph)

Other image
    mouse_pointer.png :
        https://images.wondershare.com/recoverit/article/2021/06/mouse-cursor-1.jpg
    setting.png :
        https://commons.wikimedia.org/wiki/File:GNOME_Settings_icon.svg
    hint.png :
        https://www.iconsdb.com/orange-icons/light-bulb-6-icon.html
    hint_indicator.gif, hint_indicator_placeholder.png :
        https://loading.io/spinner/ripple/-ripple-circle-scale-round-radar-radio

Sound Effect (Under res/common/raw)
    click.mp3 :
        https://youtu.be/NEy_3tQ2s3E?t=18
    explosion.mp3 :
        https://www.youtube.com/watch?v=9FMquJzgDGQ
    game_won.mp3 :
        https://www.youtube.com/watch?v=_Z3ra0CxCE0