Mobile screenshots have unique characteristics that make them both essential and challenging to work with. They're tall and narrow — typically 9:19.5 or similar aspect ratios on modern smartphones — which means traditional side-by-side layouts designed for landscape images don't work well. They often come from different devices with different resolutions — an iPhone 15 Pro Max screenshot at 1290×2796px next to a Pixel 8 screenshot at 1008×2240px needs proportional handling. And they frequently contain sensitive information — personal messages, banking apps, health data, and private photos that should never be uploaded to a third-party server for processing. MergeFrame handles all of these mobile-specific challenges. The tool proportionally fits screenshots of any resolution into equal-width grid cells, so your iPhone and Android captures sit together cleanly without cropping or distortion. The 1×2 horizontal layout places two phone screenshots side by side — ideal for iOS vs. Android app comparisons, before-and-after UI changes, and bug report documentation. The 1×3 layout stacks three screenshots for user flow documentation: login screen → main dashboard → specific feature view. The 2×2 layout creates balanced square comparisons of four mobile screens, useful for app store listing screenshots where you need to showcase multiple features. Mobile-optimized grid tips: export at 2048px width for app store screenshots — both Apple App Store and Google Play Store display screenshots at moderate resolutions, and exceeding their display dimensions wastes file size. For bug reports and internal team communication, 1500px width keeps files small for quick Slack or Jira sharing while maintaining text legibility. Add 2–4px cell borders for mobile screenshots with light backgrounds — many apps use white or near-white backgrounds, and borders prevent adjacent screenshots from visually merging. Because all processing is local, your phone screenshots — with their personal notifications, private conversations, and sensitive app data visible — stay completely on your device. The workflow is designed for the mobile-first developer and QA engineer: capture screenshots on your phone, transfer to your computer via AirDrop, cloud sync, or USB, drop them into MergeFrame, and export a clean grid in under a minute. No software to install, no account to create, no privacy concern about where your phone screenshots end up.