Best Cross-Platform App Development Companies in California

229 Companies - Rankings updated: April 04, 2026

Each agency listed on DesignRush is assessed for industry expertise and customer testimonials are evaluated in order to provide you with a vetted selection. Certain listings represent paid partnerships.

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United States × California ×

  • Top Remotely

    Top 1% Tech Talent with 1500+ In-house Developers

    Top 1% Tech Talent with 1500+ In-house Developers

    We don't just build software at Top Remotely we create solutions that work, scale, and impress. With a powerhouse team of 150+ in-house developers, we turn complex challenges into seamless digital experiences. Whether you need custom software, enterprise platforms, or next-gen IT solutions, we bring the Top  [... view Top Remotely profile ]
    Location
    Los Angeles, California
    Number of Employees
    500 - 999
    Average Hourly Rate
    $20/hr
    Minimal Budget
    $10,000 - $25,000
    View Profile

  • Start Mobile

    Your Marketplace in a Month.

    Your Marketplace in a Month.

    At Start Mobile, we create innovative online marketplaces featuring mobile apps and AI-powered by ChatGPT. Our unique approach ensures each platform is tailored to meet specific business needs, enhancing user experience and functionality. Partner with us to leverage cutting-edge technology and transform your  [... view Start Mobile profile ]
    Location
    Los Angeles, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $35/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile

  • Beehive Software

    Reimagining Software Development

    Reimagining Software Development

    Beehive is a new production model for software development (the world's first we should add) that fuses AI precision with human ingenuity. A model of collective intelligence that breaks projects into microtasks, routing them to global experts, and delivering production-ready, high quality, code faster than  [... view Beehive Software profile ]
    Location
    San Jose, California
    Number of Employees
    100 - 249
    Minimal Budget
    $10,000 - $25,000
    View Profile
    5.0 5.0 (3)

  • Blue Trail Software

    More Than Code We Build Trust Through Craft & Commitment

    More Than Code We Build Trust Through Craft & Commitment

    Engineered with integrity. Backed by mentorship. Delivered with care. BTS transforms ideas into scalable, secure, and impactful digital products that deliver long-term value.  [... view Blue Trail Software profile ]
    Location
    San Francisco, California
    Number of Employees
    100 - 249
    Average Hourly Rate
    $55/hr
    Minimal Budget
    $50,000 & Up
    View Profile

  • Appnality

    Forging Digital Realities.

    Forging Digital Realities.

    Appnality is an American software company that offers diverse mobile app development services. Be it App Concept and Strategy or UX and UI design development, Appnality has all your mobile app needs covered. Our quality assurance, testing, and data protection provide you with a fulfilling, keeping you and  [... view Appnality profile ]
    Location
    Fremont, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $50/hr
    Minimal Budget
    $10,000 - $25,000
    View Profile
    4.3 4.3 (6)

  • Endertech

    Beautiful & Functional Digital Solutions That Deliver ROI

    Beautiful & Functional Digital Solutions That Deliver ROI

    Endertech (endertech.com, 310.400.0800) is a full-service web and software development company near Los Angeles since the year 2000 providing custom design, e-commerce, software development, and online marketing support. “If you can dream it; We can build it”.  [... view Endertech profile ]
    Location
    Torrance, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $150/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile
    4.6 4.6 (19)

  • Eyfect Designs

    Experience Award Winning UX/UI Design From Us.

    Experience Award Winning UX/UI Design From Us.

    Eyfect Designs is a full-service digital agency specializing in web design, development, and mobile app solutions. We create custom, responsive websites and mobile apps tailored to your brand's needs. Our services also include SEO, digital marketing, UI/UX design, and app maintenance. We are dedicated to  [... view Eyfect Designs profile ]
    Location
    San Diego, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $35/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile

  • Allusive Digital

    Proven Excellence Through Custom Web Design and Development Services.

    Proven Excellence Through Custom Web Design and Development Services.

    Allusive Digital is a creative and marketing agency that helps businesses grow through branding, web design, content development, and digital marketing. The agency blends thoughtful strategy with polished creative execution to help clients increase visibility, strengthen their identity, and connect with their  [... view Allusive Digital profile ]
    Location
    Los Angeles, California
    Number of Employees
    Under 49
    View Profile
    5.0 5.0 (5)

  • Phoenix Afterglow

    Your Full Digital Development Experience.

    Your Full Digital Development Experience.

    Phoenix Afterglow is a premier multimedia company specializing in web development, app development, online marketing, and cybersecurity. They are dedicated to upholding the highest standards of performance, integrity, and ethics to ensure client satisfaction and achieve a lasting sense of fulfillment for all  [... view Phoenix Afterglow profile ]
    Location
    Irvine, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $50/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile
    5.0 5.0 (7)

  • Fortunesoft IT Innovations

    Industry-Specific, Ready To Deploy Solutions That Drive Results

    Industry-Specific, Ready To Deploy Solutions That Drive Results

    Fortunesoft is an AI-driven digital engineering and solutions company specializing in Healthcare, Life Sciences, and Fintech.  [... view Fortunesoft IT Innovations profile ]
    Location
    Sunnyvale, California
    Number of Employees
    50 - 99
    Minimal Budget
    $10,000 - $25,000
    View Profile

  • Atlantis

    Straight hands. Hot heads.

    Straight hands. Hot heads.

    We use the best world practices (YAGNI, KISS, DRI, and SOLID). An enterprise approach is an advantage, not an excuse. An extreme approach to development allows us to resort to the use of development-driven methodologies, in particular design, domain, bound, and testing.  [... view Atlantis profile ]
    Location
    Newport Beach, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $50/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile

  • devAtelier

    Southern Californias Mobile App experts since 2009

    Southern Californias Mobile App experts since 2009

    We are San Diego's mobile-native and mobile-first consultancy. We specialize in Swift for iOS, Flutter for iOS/Android, and React for Web. We have led projects for Fortune 500 companies and startups. If you're looking for an easy-to-talk-to and experienced partner to build your app, call devAtelier!  [... view DevAtelier profile ]
    Location
    San Diego, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $125/hr
    Minimal Budget
    $10,000 - $25,000
    View Profile

  • RSunBeat Software

    Your Vision, Our Innovation Together, We Build the Future.

    Your Vision, Our Innovation Together, We Build the Future.

    RSunBeat Software is a globally trusted leader in mobile app development, serving businesses in the USA, UK, Australia, Italy, Dubai, Brazil, and more. We design innovative, high-quality apps that boost growth, elevate user experiences, and turn ideas into powerful digital solutions.  [... view RSunBeat Software profile ]
    Location
    California City, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $15/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile

  • FACTn Software

    Empowering Innovation, Connecting Excellence

    Empowering Innovation, Connecting Excellence

    FACTn Software, your trusted partner in software engineering outsourcing solutions. Founded with a passion for technological innovation and a commitment to excellence, FACTn Software is dedicated to providing top-tier software engineering talent to companies in the Scandinavian region and beyond.  [... view FACTn Software profile ]
    Location
    Los Angeles, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $45/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile
    5.0 5.0 (6)

  • Source Code Lab

    Best Game Development Company in USA.

    Best Game Development Company in USA.

    Source Code Lab is the Best Custom Game Development Company in Usa/India.Our game developers build remarkable games compatible with the most popular platforms to attract the attention of a wider audience.  [... view Source Code Lab profile ]
    Location
    San Francisco, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $25/hr
    Minimal Budget
    Under $1,000
    Portfolios Count
    1 Project Listed
    View Profile
    5.0 5.0 (8)

  • MobMaxime

    Top Mobile App and Web Development Company in Canada, USA and UK

    Top Mobile App and Web Development Company in Canada, USA and UK

    We design highly polished iPhone, Android and Web Apps for startups and Enterprise clients.  [... view MobMaxime profile ]
    Location
    Sunnyvale, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $15/hr
    Minimal Budget
    $10,000 - $25,000
    Portfolios Count
    3 Projects Listed
    View Profile

  • TechMave Software

    You Think We Will Deliver

    You Think We Will Deliver

    TechMave Software LLP delivers innovative web, mobile, and AI solutions tailored to business needs. Our team combines creativity, technology, and strategy to build impactful digital products that empower brands globally.  [... view TechMave Software profile ]
    Location
    Mountain View, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $11/hr
    Minimal Budget
    $10,000 - $25,000
    View Profile
    5.0 5.0 (21)

  • Rytsense Technologies

    Leading Global Digital Transformation

    Leading Global Digital Transformation

    Rytsense Technologies is an AI-driven technology company specializing in AI development services, machine learning solutions, and intelligent automation. We help businesses build advanced AI applications, integrate AI models into existing systems, and transform data into actionable insights.  [... view Rytsense Technologies profile ]
    Location
    Mountain View, California
    Number of Employees
    100 - 249
    Average Hourly Rate
    $25/hr
    Minimal Budget
    Under $1,000
    View Profile
    5.0 5.0 (64)

  • Umang Software Technologies

    UMANG means Enthusiasm; Enthusiasm is what drives the mankind!

    UMANG means Enthusiasm; Enthusiasm is what drives the mankind!

    Umang has been working with some of the elite organization across the globe to develop and maintain their existing legacy applications. They are experts in developing custom software/Mobile/Web applications.Umang has expertise in Delphi, Java, PHP, Python, DotNet and 20+ other technologies and has domain  [... view Umang Software Technologies profile ]
    Location
    San Jose, California
    Number of Employees
    Under 49
    View Profile

  • DS Technologies (Pvt.) Limited

    Global Web Development & Digital Marketing Experts

    Global Web Development & Digital Marketing Experts

    DS Technologies is a global web design, development, and digital marketing agency. We specialize in creating innovative, custom solutions that drive measurable results. With expertise in SEO, UI/UX, and scalable web applications, we help businesses worldwide grow their digital presence and achieve sustainable  [... view DS Technologies (Pvt.) Limited profile ]
    Location
    Los Angeles, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $25/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile
    4.7 4.7 (27)

  • Altiux Innovations Pvt. Ltd.

    We help accelerate your IoT!

    We help accelerate your IoT!

    Altiux Innovations is a software and product engineering services organization focused on helping you accelerate the development of your IoT solutions and products. We provide specialized engineering services across the entire IoT development cycle, from consulting, device engineering, cloud and mobility  [... view Altiux Innovations Pvt. Ltd. profile ]
    Location
    Milpitas, California
    Number of Employees
    50 - 99
    Minimal Budget
    $1,000 - $10,000
    Portfolios Count
    1 Project Listed
    View Profile
    4.4 4.4 (50)

  • Persistent

    See Beyond, Rise Above.

    See Beyond, Rise Above.

    Persistent Systems, a renowned global leader in software product development and technology services. Delve into our innovative offerings to stay ahead in the ever-evolving landscape of technology.  [... view Persistent profile ]
    Location
    Santa Clara, California
    Number of Employees
    1000 & Up
    Average Hourly Rate
    $100/hr
    Minimal Budget
    $50,000 & Up
    View Profile
    4.6 4.6 (730)

  • Opal Infotech

    We Build Success Stories

    We Build Success Stories

    For over 2 decades, starting in 1998, we have been serving a global clientele with web design, web development, mobile app development & digital marketing services. Our expertise spans SEO, Google Ads, Alibaba minisites & ranking optimization & the ongoing maintenance of apps and websites across more than 75  [... view Opal Infotech profile ]
    Location
    Dublin, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $50/hr
    Minimal Budget
    $10,000 - $25,000
    View Profile
    4.8 4.8 (212)

  • iCode49 Technolabs

    4 Steps to Cloud 9

    4 Steps to Cloud 9

    iCode49 Technolabs stands out as a premier provider specializing in the meticulous development of cutting-edge iOS and Android mobile applications uniquely crafted for both startups and global brands. Our expertise lies in driving innovation within the ever-evolving mobile landscape, where we leverage our  [... view ICode49 Technolabs profile ]
    Location
    Los Angeles, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $20/hr
    Minimal Budget
    $10,000 - $25,000
    View Profile
    5.0 5.0 (12)

  • Chipsy IT Services Pvt. Ltd.

    Transform Your Business with Our End-to-End IT Solutions.

    Transform Your Business with Our End-to-End IT Solutions.

    Chipsy Information Technology Services Pvt Ltd. offers comprehensive IT solutions, including expert consulting, mobile app development (VitalBase is an ABDM-enabled hospital management information system), application development, school management systems, and DevOps services.  [... view Chipsy IT Services Pvt. Ltd. profile ]
    Location
    San Francisco, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $12/hr
    View Profile

  • CONTUS Tech

    Your Digital Growth Success Partner.

    Your Digital Growth Success Partner.

    CONTUS Tech stands as a prominent global authority in digital engineering services, heralded for its transformative impact on businesses worldwide. Our forte lies in crafting cutting-edge digital products, pioneering connected vehicle experiences, and spearheading next-generation streaming services that  [... view CONTUS Tech profile ]
    Location
    Santa Clara, California
    Number of Employees
    250 - 499
    Average Hourly Rate
    $30/hr
    Minimal Budget
    $25,000 - $50,000
    View Profile
    4.0 4.0 (314)

  • Fourchain Technologies Private Limited

    Redefine your Business Growth with Fourchain Technologies.

    Redefine your Business Growth with Fourchain Technologies.

    At Fourchain, we specialize in modernizing businesses by offering comprehensive digital transformation solutions like blockchain, artificial intelligence, fintech and application development services, all tailored to meet the specific pain points and unique needs of startups, mid-size, and enterprise  [... view Fourchain Technologies Private Limited profile ]
    Location
    Ontario, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $30/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile
    5.0 5.0 (21)

  • Invoxico Technologies

    Crafting Websites, Creating Success!

    Crafting Websites, Creating Success!

    Invoxico Technologies is an adept company in web design and development, acknowledged for its proficiency in crafting customized digital solutions. Their expert team focuses on UI/UX design, web development, CMS development, eCommerce solutions, and mobile app development, and offers a complete range of  [... view Invoxico Technologies profile ]
    Location
    La Puente, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $30/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile
    5.0 5.0 (10)

  • TST Technology

    Your Trusted IT Consulting Company for Business Success.

    Your Trusted IT Consulting Company for Business Success.

    TST Technology is an IT consulting company that offers services such as UI/UX design, web and mobile app development, software development, and SaaS product development. They have completed over 40 projects across 15+ industries.  [... view TST Technology profile ]
    Location
    Los Angeles, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $50/hr
    Minimal Budget
    $1,000 - $10,000
    View Profile
    5.0 5.0 (22)

Related Services in California

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