Alternatives

Products that do what InboxSDK by Streak (YC S11) – Build Apps inside Gmail does

1. 1OS
   Open-Sourcing InboxSDK (YC S11) – Build Apps in Gmail▲257

   Hi HN! We’re Aleem, Chris, Borys, Meichen and Zach from Streak (YC S11) and today we’re open sourcing our InboxSDK https://www.inboxsdk.com, which makes it easy to build apps for Gmail. Over 1.8B users spend their days in Gmail! Having your app built into the Gmail workflow is a better user experience and gives you great user retention. InboxSDK gives you a high-level, declarative API to insert your UI into Gmail without having to directly manipulate the DOM yourself. End users install a browser extension to use your app. The SDK can add UI to multiple areas of Gmail. For example,…

   2022

2. 2
   InboxSDK▲508

   First usable API to write Gmail Apps for 1B active users

   2015

3. 3SC
   Streak.com - Do sales, support and bug tracking all inside Gmail▲306

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4. 4
   Streak▲363

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5. 5
   Inbox by Google▲1,148

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6. 6
   New Gmail▲935

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   2018 · blog.google

7. 7
   Inbox Zero Tabs▲400

   Split inbox tabs for Gmail. 100% private. 100% free

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8. 8
   Streak 3▲208

   The "low-work" CRM inside Gmail

   2020

9. 9
   FiloMail for Android▲140

   AI Gmail client that turns emails into clear tasks

   Jan 2026

10. 10
    Inboxer▲212

    A clean, open-source desktop client for Google Inbox 💌

    2018

11. 11
    Mailmodo 2.0 (YC S21)▲354

    Interactive email marketing made easier

    2024

12. 12SE
    Signal – Edit emails in your Gmail inbox▲151

    2013 · trysignal.com

13. 13
    Gmail in the Gemini Era▲375

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    Jan 2026

14. 14MA
    Mimestream, a native macOS email client for Gmail▲403

    2020 · mimestream.com

15. 15
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    2018

16. 16
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    CRM inside Gmail, now with contacts

    2016

17. 17
    MailToDock▲70

    Turn Gmail into Google Tasks with AI-powered

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18. 18
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    Transform your Gmail into organized task lists

    2017

19. 19EE
    Easy Email Encryption inside Gmail (Alpha, Open-Source)▲170

    2013 · streak.com

20. 20GJ
    Gmail.js – JavaScript API for Gmail▲212

    2013 · github.com

21. 21
    Gmail for Android ▲85

    Big Android update introducing a unified inbox

    2015

22. 22DY
    Download your Gmail emails as PDFs (built with InboxSDK)▲9

    2015 · getduffel.com

23. 23
    InboxPro▲174

    Boost your productivity & turn Gmail into a powerful machine

    2022

24. 24
    Asana for Gmail▲216

    Turn emails into tasks without leaving your Gmail inbox

    2017

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