Duo app icon

Apps Like Duo for iPhone and iPad

Test responsive web design views simultaneously.

The app displays a desktop and mobile view simultaneously for responsive web design testing. Users can navigate both panes with synchronized browsing and access WebKit Dev Tools for debugging.

by Electric Pulp★ 0.00 ratingsDeveloper Tools$4.99Data updated 2026-10-25
App detailsView in App Store

Duo screenshots

Ranked alternatives

Showing 381–400 of 1,000 ranked alternatives.

  1. RizzFlix app icon

    RizzFlix

    Smart Bros Ltd co

    ★ 4.99 ratingsGraphics & DesignFreeData updated 2026-09-06
    App details
  3. Password Crypt Extension app icon

    Password Crypt Extension

    Password Crypt ApS

    Store credentials securely online

    Secure manager stores and manages credentials for personal and organizational use. Access credentials via web browser without installation. No ads or tracking. Sync across devices. Manage multiple accounts and passwords. Protect data with encryption.

    ★ 0.00 ratingsUtilitiesFreeData updated 2026-09-06
    App details
  5. Source 3 app icon

    Source 3

    Street Coder LLC

    View HTML source of any page.

    The app provides a Safari extension to view the HTML source of any web page. It offers customizable syntax highlighting for web developer tasks.

    ★ 4.310 ratingsDeveloper Tools$0.99Data updated 2026-11-12
    App details
  6. FontPreview app icon

    FontPreview

    Compumaster Ltd

    Compare installed fonts side-by-side.

    The app displays font previews in a multi-column list interface. Users can scroll through lists and compare fonts side-by-side, with search boxes for each column.

    ★ 0.00 ratingsUtilities$0.99Data updated 2026-09-30
    App details
  8. Learn Backend Web Development app icon

    Learn Backend Web Development

    Shahbaz Khan

    Skills with code tutorials

    With tutorials on PHP, Node.js, Python, Ruby on Rails, ASP.NET, Django, and Flask. Follow step-by-step guides to build websites and web apps. Access code examples and practice exercises to reinforce concepts.

    ★ 5.04 ratingsEducation$2.99Data updated 2026-10-04
    App details
  9. Masquerade app icon

    Masquerade

    Riccardo Lardi

    Mask desktop parts for better focus

    The app masks parts of the user's desktop, allowing them to see only a certain area while the rest is hidden. It offers a resizable mask with adjustable transparency and color, and hides the screen after mouse inactivity.

    ★ 0.00 ratingsUtilitiesFreeData updated 2026-11-08
    App details

How we rank alternatives

Apps are ranked by functional similarity, category fit, rating confidence, and popularity.