MALClient is 3rd party app for managing your anime and manga list on MyAnimeList.net as well as accessing other website features.

It allows you to:
• Browse your own list as well as others'.
• Update your anime entries.
• Read anime reviews.
• Browse related anime.
• View top anime and manga in various categories.
• Search for characters!
• Check Character&Staff details.
• Read MAL News&Articles.
• View your watching/reading history.
• Watch promotional videos.
• Manage favourite shows, characters etc.
• Browse most recent recommendations.
• Build your weekly calendar with currently airing shows.
• Add widget with shows airing today.
• And much more!

Additionally it allows to access social aspects of service with features like:
• Forum
• Private Messaging
• Comment Conversations
• Notifications
• Friends Feeds
• Browse, join and chat in MAL clubs.

To top it off it's fully open sourced.

As for in-app purchases; they are all donations so don't worry about them :)

// Option A //

To download MALClient mod from HappyMod.com.
You need enable the option "Unknown Sources".
1. Click on the above link to download MALClient mod APK.
2. Save the file in your device Downloads folder.
3. Now tap on Install and wait for the installation to finish.
4. Once it is done, open the game and start playing it right away.

// Option B //

To download MALClient from HappyMod APP, you can follow this:
1. Open your browser and download the HappyMod APK file from HappyMod.com - the only official website of HappyMod.
2. Open Android Settings and go into Privacy or Security.
3. Tap the option to Allow Unknown Sources and enable it.
4. Go to your Android downloads and tap the APK file.
5. Follow the directions on the screen to install it.
6. Search MALClient in HappyMod App.