Click 2 Tally Lite

You can keep track of multiple counters at once and organize them into "Counting Boards". Choose how much to count by ("step") and what to start at. Negative and non-whole numbers are supported. Numbers can be very large. You can also convert numbers to tallies (integers 1-99,999). There are various settings. The full version has a home screen widget and exclusive customization features.

Lite Version Features
• Keep track of multiple counters on multiple counting boards
• Convert numbers to tallies
• Counter step size and starting point options
• Option to use volume buttons to count
• Export and import counters in settings menu

Extra Full Version Features
• 5 theme choices: Auto, Dark, Light, Black Out, and Light Amber
• Counter widget for your home screen
• Change color of counters
• Field to type in current counter steps

Full Version Link
https://play.google.com/store/apps/details?id=com.grantojanen.counter

More Details
Offline: Yes
Lightweight: Yes, < 1MB
Multi-Window Support (Android 7+): Yes