Best Cross-Platform App Development Companies in California

79 Companies-Rankings updated: September 04, 2026

Each agency undergoes DesignRush evaluation for professional expertise and genuine client satisfaction to assist your search. Some featured placements are paid.

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United States × California × Cross-Platform Mobile App Development × Software & IT Services ×Clear Filters

  • NEKLO

    AI-driven custom software development for complex, high-growth industries.

    NEKLO is an international custom software development partner. Since 2008, weve specialized in building and scaling digital products for high-stakes industries, including Healthcare, Fintech, Energy, and Construction...

    Top Services:

    • AI Development
    • Software Development
    • Mobile App Development
    • Product Design
    • Software Testing
    • Show more
    Location
    Burlingame, California
    Number of Employees
    100 - 249
    Average Hourly Rate
    $35/hr
    Minimal Budget
    $1,000 - $10,000
    Portfolios Count
    4 Projects Listed
    Visit WebsiteView Profile

  • Techjays

    The Best Way To Build Your Software.

    Our focus is on providing businesses with the tools they need to reach their maximum potential through the use of our cutting-edge software solutions. Launch your product to market 2x faster with Techjay's strong business domain experience, technical expertise, extensive knowledge of the latest industry...

    Top Services:

    • Software Testing
    • Software Development
    • Mobile App Development
    • Web Development
    • UI/UX Design
    • Show more
    Location
    Menlo Park, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $28/hr
    Minimal Budget
    $10,000 - $25,000
    Visit WebsiteView Profile
    5.0 5.0 (8)

  • L+R

    End-to-end digital product design and engineering.

    End-to-end digital product design and engineering for enterprises and premium brands...

    Top Services:

    • Branding
    • Mobile App Development
    • Software Development
    • AI Development
    • Design Services
    • Show more
    Location
    Los Angeles, California
    Number of Employees
    Under 49
    Minimal Budget
    $25,000 - $50,000
    Portfolios Count
    4 Projects Listed
    Visit WebsiteView Profile
    5.0 5.0 (7)

  • PRIME IT

    Innovative Web & Custom Soft Development Solutions

    DESIGN, DEVELOP, DEPLOY!!! The PRIME is a team of highly skilled and experienced professionals in the field of Web Development and Custom Software Development PRIME means - Punctuality, Quickness, Honesty and Professional work! WE HAVE GOT YOU COVERED!!!...

    Top Services:

    • Software Development
    • Mobile App Development
    • Web Development
    • Web Design
    • UI/UX Design
    • Show more
    Location
    Los Angeles, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $50/hr
    Minimal Budget
    $10,000 - $25,000
    Portfolios Count
    4 Projects Listed
    Visit WebsiteView Profile

  • Forge Studio

    Senior Product Designers Embedded in Your Team — Design Systems, Staff Augmentation, and Zero-to-One

    Forge Studio places senior product designers (L4-L6 caliber) from Coinbase, Roblox, and Instacart directly into your team. Embedded design teams, enterprise design systems, and zero-to-one product design. $9.5M+ in engagements since 2017...

    Top Services:

    • UI/UX Design
    • Web Design
    • Product Design
    • Digital Strategy
    • AI Development
    • Show more
    Location
    San Francisco, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $200/hr
    Minimal Budget
    $10,000 - $25,000
    Portfolios Count
    2 Projects Listed
    Visit WebsiteView Profile

  • LuminoGuru

    Innovative and intelligent technology solutions and services

    If we break down the essence of Luminoguru, it is made up of two words: 'Lumino' meaning 'Light' and 'Guru' meaning 'Teacher'. In the realm of work, light symbolizes clarity and inspiration. Like a guiding beacon, it lightens up ideas, nurtures creativity, and transforms the workspace into a realm where...

    Top Services:

    • Mobile App Development
    • Software Development
    • Web Development
    • eCommerce Development
    • IoT
    • Show more
    Location
    Nevada City, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $20/hr
    Minimal Budget
    $1,000 - $10,000
    Visit WebsiteView Profile
    4.6 4.6 (3)
    4.2 4.2 (51)

  • Simtech Development

    Skyrocket Your Business With eCommerce Development.

    End-to-end eCommerce website development and infrastructure solutions for B2B, B2C, and D2C proven by our 1000+ happy clients in 170 countries...

    Top Services:

    • eCommerce Development
    • Web Development
    • Mobile App Development
    • Web Design
    • UI/UX Design
    • Show more
    Location
    San Diego, California
    Number of Employees
    250 - 499
    Average Hourly Rate
    $40/hr
    Minimal Budget
    $1,000 - $10,000
    Visit WebsiteView Profile

  • Tech.us, Inc

    Build Better Software.

    Tech.us is an AI software solutions company that provides AI development, mobile applications, cloud consulting, and IT services. We focus on creating secure, scalable, and innovative technologies that support businesses in their digital journey...

    Top Services:

    • AI Development
    • Mobile App Development
    • IT Services
    • Software Testing
    • Cybersecurity
    • Show more
    Location
    San Jose, California
    Number of Employees
    100 - 249
    Minimal Budget
    $10,000 - $25,000
    Visit WebsiteView Profile

  • ACubetech Solutions Private Limited

    Take Charge Of Your Business Continuity

    ACUBE USAL LLC is a US registered custom Software development company delivering solutions in web, mobile & AI-driven solutions to companies across the US, Europe and Australia. We have proven experience in delivering solutions into education, healthcare, real-estate, E-commerce, logistics, food compliance...

    Top Services:

    • Mobile App Development
    Location
    Nevada City, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $20/hr
    Minimal Budget
    $1,000 - $10,000
    Portfolios Count
    1 Project Listed
    Visit WebsiteView Profile

  • WebMovement LLC

    Software Engineering Design Results.

    Our expertise lies in the orchestration and direction of software engineering teams, meticulously crafting custom solutions tailored to the unique needs of our clients. We specialize in the biotech, life science, and healthcare sectors, and we leverage our deep domain knowledge to deliver cutting-edge...

    Top Services:

    • Mobile App Development
    • Software Development
    • eCommerce Development
    • Web Development
    • Digital Marketing
    • Show more
    Location
    San Diego, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $100/hr
    Minimal Budget
    $10,000 - $25,000
    Visit WebsiteView Profile

  • AlphaSquad Technologies

    We Elevate Brands From Good to Great.

    At AlphaSquad Technologies, we transcend mere development to craft transformative digital experiences. With unmatched proficiency in Web Development and Mobile Application Development, we pave the way toward an innovative, digitally evolved landscape. Our specialization lies in pioneering Website Design...

    Top Services:

    • Mobile App Development
    • Digital Services
    • Product Design
    • Web Design
    • UI/UX Design
    • Show more
    Location
    San Francisco, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $25/hr
    Minimal Budget
    $1,000 - $10,000
    Visit WebsiteView Profile

  • Ideators

    Digitize Your Ideas!

    Ideators, an Incorporated Registered Firm with a presence & clientele in Florida, Texas, Boston, San Francisco, Australia, Hong Kong, & Portugal is an emerging Digital Services & Solutions Firm. We ensure to integrate the expertise of the team professionals along with innovativeness, and your requir...

    Top Services:

    • Software Development
    • Software Testing
    • Mobile App Development
    • IT Services
    • Managed Services
    • Show more
    Location
    San Francisco, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $25/hr
    Minimal Budget
    $1,000 - $10,000
    Visit WebsiteView Profile

  • Zavod-IT

    We Build Tomorrow, Today

    With 15 years of experience, we specialize in developing startups, cryptocurrency exchanges, cashback platforms, Telegram bots, and complex software solutions for clients across the USA and Europe. Our expertise guarantees tailored, high-quality solutions for diverse industries and business needs...

    Top Services:

    • Software Development
    • Web Development
    • UI/UX Design
    • eCommerce Development
    • Blockchain
    • Show more
    Location
    San Francisco, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $60/hr
    Visit WebsiteView Profile

  • In Time Tec South Korea

    Best award-winning software development company in South Korea.

    Time Tec South Korea is a top-rated, multi-award-winning software development company providing a full suite of services and solutions like mobile application development, software development, Microsoft Dynamics 365 development, web development, ServiceNow consulting, and cybersecurity consulting to small...

    Top Services:

    • Software Development
    • Mobile App Development
    • Cybersecurity
    • AI Development
    • Show more
    Location
    Roseville, California
    Number of Employees
    1000 & Up
    Average Hourly Rate
    $25/hr
    Minimal Budget
    $1,000 - $10,000
    Visit WebsiteView Profile

  • Fishermen Labs

    Top Augmented Reality & Virtual Reality Agency

    An Immersive Media Agency specializing in the development of Extended Reality (XR, AR, VR, MR) experiences driving meaningful connections between brands & consumers. Our global team of skilled designers, artists, and developers craft creative narratives & experiences powered by emerging tech...

    Top Services:

    • VR/AR
    • Web Development
    • Mobile App Development
    • Product Design
    • Web Design
    • Show more
    Location
    Culver City, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $200/hr
    Minimal Budget
    $10,000 - $25,000
    Visit WebsiteView Profile

  • Tap Built

    Tap Built, located in California, creates innovative mobile apps and engaging games for entrepreneur

    Tap Built Located in California creates innovative mobile apps and engaging games for entrepreneurs startups and business worldwide...

    Top Services:

    • Mobile App Development
    • UI/UX Design
    • Blockchain
    Location
    West Covina, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $100/hr
    Minimal Budget
    $1,000 - $10,000
    Visit WebsiteView Profile

  • Top Remotely

    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...

    Top Services:

    • Mobile App Development
    • Software Development
    • DevOps Consulting
    • IT Services
    • Web Development
    • Show more
    Location
    Los Angeles, California
    Number of Employees
    500 - 999
    Average Hourly Rate
    $20/hr
    Minimal Budget
    $10,000 - $25,000
    Visit WebsiteView Profile

  • Beehive Software

    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...

    Top Services:

    • Web Development
    • Software Development
    • AI Development
    • Mobile App Development
    • IoT
    • Show more
    Location
    San Jose, California
    Number of Employees
    100 - 249
    Minimal Budget
    $10,000 - $25,000
    Visit WebsiteView Profile
    5.0 5.0 (4)

  • Endertech

    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”...

    Top Services:

    • Digital Services
    • Web Development
    • Web Design
    • eCommerce Development
    • Software Development
    • Show more
    Location
    Torrance, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $150/hr
    Minimal Budget
    $1,000 - $10,000
    Visit WebsiteView Profile
    4.6 4.6 (19)

  • Teamvoy

    We Bring The Tech. You Get The Wins.

    Teamvoy is an AI engineering and transformation partner. We help companies make smarter technology decisions and turn them into production-ready software...

    Top Services:

    • Software Development
    • AI Development
    • Design Services
    • Web Design
    • UI/UX Design
    • Show more
    Location
    Covina, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $50/hr
    Minimal Budget
    $10,000 - $25,000
    Visit WebsiteView Profile
    4.7 4.7 (29)

  • devAtelier

    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!...

    Top Services:

    • Mobile App Development
    • Software Development
    • IoT
    • Web Development
    • Show more
    Location
    San Diego, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $125/hr
    Minimal Budget
    $10,000 - $25,000
    Visit WebsiteView Profile

  • FACTn Software

    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...

    Top Services:

    • Software Development
    • Mobile App Development
    • AI Development
    • Cloud Consulting
    • Managed Services
    • Show more
    Location
    Los Angeles, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $45/hr
    Minimal Budget
    $1,000 - $10,000
    Visit WebsiteView Profile
    5.0 5.0 (10)

  • Born West Inc.

    We Build Digital Products, Experiences, And Systems ‍that Matter.

    Born West is a creative tech agency. We turn ambitious ideas into working software from inception to launch. Our senior strategists, designers, and engineers work as one team to shape digital products, AI-powered tools, platforms, and experiences that are thoughtful, scalable, and built to ship...

    Top Services:

    • Product Design
    • Web Design
    • eCommerce Development
    • Web Development
    • WordPress Website Design
    • Show more
    Location
    Concord, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $200/hr
    Visit WebsiteView Profile

  • Source Code Lab

    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...

    Top Services:

    • Graphic Design
    • IT Services
    • VR/AR
    • Mobile App Development
    • Wearables
    • Show more
    Location
    San Francisco, California
    Number of Employees
    50 - 99
    Average Hourly Rate
    $25/hr
    Minimal Budget
    Under $1,000
    Portfolios Count
    1 Project Listed
    Visit WebsiteView Profile
    5.0 5.0 (8)

  • Rytsense Technologies

    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...

    Top Services:

    • AI Development
    • Mobile App Development
    • Software Development
    • Business Consulting
    • Show more
    Location
    Mountain View, California
    Number of Employees
    100 - 249
    Average Hourly Rate
    $25/hr
    Minimal Budget
    Under $1,000
    Visit WebsiteView Profile
    5.0 5.0 (67)

  • DS Technologies (Pvt.) Limited

    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...

    Top Services:

    • Graphic Design
    • Web Design
    • eCommerce Development
    • Web Development
    • UI/UX Design
    • Show more
    Location
    Los Angeles, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $25/hr
    Minimal Budget
    $1,000 - $10,000
    Visit WebsiteView Profile
    4.7 4.7 (27)

  • Persistent

    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...

    Top Services:

    • AI Development
    • Software Development
    • Web Development
    • Mobile App Development
    • Blockchain
    • Show more
    Location
    Santa Clara, California
    Number of Employees
    1000 & Up
    Average Hourly Rate
    $100/hr
    Minimal Budget
    $50,000 & Up
    Visit WebsiteView Profile
    4.6 4.6 (730)

  • CONTUS Tech

    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...

    Top Services:

    • DevOps Consulting
    • IT Services
    • Mobile App Development
    • IoT
    • Digital Services
    • Show more
    Location
    Santa Clara, California
    Number of Employees
    250 - 499
    Average Hourly Rate
    $30/hr
    Minimal Budget
    $25,000 - $50,000
    Visit WebsiteView Profile
    4.0 4.0 (314)

  • Invoxico Technologies

    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...

    Top Services:

    • Web Design
    • eCommerce Development
    • UI/UX Design
    • Web Development
    • WordPress Website Design
    • Show more
    Location
    La Puente, California
    Number of Employees
    Under 49
    Average Hourly Rate
    $30/hr
    Minimal Budget
    $1,000 - $10,000
    Visit WebsiteView Profile
    5.0 5.0 (10)

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