Open source focus

Open Source Alternatives to CallApp

12 open source Mobile App options similar to CallApp, ranked by named competitors first, sector overlap, and our 0-100 AI-readiness score. Every company listed publishes its source: each one carries an open source sector tag and a public GitHub repository.

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United Manufacturing Hub Systems54
ManufacturingCologne, Germany$5.4M
An open-source data platform for manufacturers to access and structure machine data.
Open source · Self-hostable
Mozilla Firefox54
InternetSan Francisco, United States$2.3M
Open-source web browser focused on privacy, user control, and an open internet.
Open source · Self-hostable
Nextcloud52
Cloud ComputingNuremberg, Germany$63.0M
Open-source, self-hosted file sync and share and collaboration platform.
Open source · Self-hostable
Arduino46
Open SourceSomerville, United States$54.0M
Open-source hardware and software company providing microcontrollers and kits for digital devices.
Open source · Self-hostable
Open Bitcoin Tracker23
Fintech
A privacy-focused, open-source Android app to track Bitcoin value without accounts or analytics.
Open source · Self-hostable
Manyverse21
Decentralized Social Network
Manyverse is a social network client that uses a peer-to-peer protocol, allowing users to create and share content offline and without central servers.
Open source · Self-hostable
Apache HTTP Server18
Open SourceWakefield, United States
A free, open-source, cross-platform web server software managed by the Apache Software Foundation.
Open source · Self-hostable
EU
Euro-Office10
SoftwareEurope
A sovereign, open-source office suite for European enterprises and public administrations.
Open source · Self-hostable
EU
Eurostack10
SoftwareEurope
A European enterprise contributing to the development of sovereign digital infrastructure.
Open source · Self-hostable
Signal9
MessagingWashington, United States
End-to-end encrypted messaging and voice calling app focused on privacy and security.
Open source
Freetube9
Consumer App
Free, open-source YouTube client for iPhone and iPad. Watch YouTube without ads, download videos from YouTube, Instagram, TikTok, X and 2,000+ sites. Background audio, AirPlay, PiP. Sideload with a free Apple ID.
Open source
XWiki2
SoftwareParis, France
Open-source enterprise wiki and collaboration software.
Open source · Self-hostable

Company	Sector	License	HQ	Funding	Score
United Manufacturing Hub SystemsAn open-source data platform for manufacturers to access and structure machine data.	Manufacturing	Open source · Self-hostable	Cologne, Germany	$5.4M	54
Mozilla FirefoxOpen-source web browser focused on privacy, user control, and an open internet.	Internet	Open source · Self-hostable	San Francisco, United States	$2.3M	54
NextcloudOpen-source, self-hosted file sync and share and collaboration platform.	Cloud Computing	Open source · Self-hostable	Nuremberg, Germany	$63.0M	52
ArduinoOpen-source hardware and software company providing microcontrollers and kits for digital devices.	Open Source	Open source · Self-hostable	Somerville, United States	$54.0M	46
Open Bitcoin TrackerA privacy-focused, open-source Android app to track Bitcoin value without accounts or analytics.	Fintech	Open source · Self-hostable	—	—	23
ManyverseManyverse is a social network client that uses a peer-to-peer protocol, allowing users to create and share content offline and without central servers.	Decentralized Social Network	Open source · Self-hostable	—	—	21
Apache HTTP ServerA free, open-source, cross-platform web server software managed by the Apache Software Foundation.	Open Source	Open source · Self-hostable	Wakefield, United States	—	18
EUEuro-OfficeA sovereign, open-source office suite for European enterprises and public administrations.	Software	Open source · Self-hostable	Europe	—	10
EUEurostackA European enterprise contributing to the development of sovereign digital infrastructure.	Software	Open source · Self-hostable	Europe	—	10
SignalEnd-to-end encrypted messaging and voice calling app focused on privacy and security.	Messaging	Open source	Washington, United States	—	9
FreetubeFree, open-source YouTube client for iPhone and iPad. Watch YouTube without ads, download videos from YouTube, Instagram, TikTok, X and 2,000+ sites. Background audio, AirPlay, PiP. Sideload with a free Apple ID.	Consumer App	Open source	—	—	9
XWikiOpen-source enterprise wiki and collaboration software.	Software	Open source · Self-hostable	Paris, France	—	2