LongShot is a free Android app helps users take long screenshots, capture scrolling windows, capture long web page in a shot.

Take long screenshots on Android devices, stitch multiple screenshots/images into a pixel-perfect long one, or capture long web page directly. Plus a handy tool for taking multiple screenshots. LongShot is a great app for taking long screenshots of conversations, web pages, threads, etc.
LongShot Screenshot & Capture Features:
- Automatically merge multiple screenshots/images into one vertically or horizontally, with a bunch of options.
- Auto scroll (Android 7.0+ only).
- Auto capture screenshots after scrolling.
- Floating screenshot capturing buttons make take multiple screenshots like a breeze.
- Powerful manual stitching tool to fine-tune a pixel-perfect long image.
- Capture long web page by only 2 clicks: set start position (optional), set end position – done!
- No watermarks, all features are free, and non-intrusive (closable) ads.
Capture long screenshot
You have different options to capture a scrolling window on Android phone: Auto Scroll, Speed Mode and Manual Capture.
Auto Scroll
On devices running Android 7 or above, the LongShot app can scroll screen automatically via accessibility service. You need to enable it in Settings > Accessibility > LongShot.

When it turned on, after you hit Start button while capturing, the screen will be scrolled automatically. A red line will show up at the process. Once it scrolled to the position you want to end, click the area above the red line to stop capturing.
Speed Mode
It improves stitching speed and accuracy for vertical long screenshot.
If you want to stitch horizontal screenshots or stitching without merging overlap parts, you should disable it.
Manual Capture
In Manual capture mode, you take screenshots one by one by tapping the floating Capture button. After that you will have the options to stitch them together using the screenshot app.

Capture long web pages, scrolling windows

Capture long web page by only 2 clicks: set start position (optional), scroll down to the position and set end position – done!
Download
Download the free app on Google Play Store here.
Long screenshot alternatives
Many smartphone makers have the built-in option to help users capture long screenshots without any third-party apps.
Pingback: Take long screenshots on Huawei phone – MANY Android apps