Freelance and remote App developers jobs

Develop and support a mobile or web application on-site. The project scope, target platforms, features, and technical requirements will be defined with the selected freelancer. Please be prepared to collaborate in person, contribute to implementation decisions, and deliver clean, maintainable application code. Experience with app development workflows, testing, and deployment is preferred. Read more

Build an initial web application for a late-night food runner/delivery service, with the goal of evolving it into a full-scale app over time. The service should support customers placing food delivery requests after midnight and runners fulfilling those orders. The first version should establish the core user flow, including a customer-facing ordering/request experience and the operational foundations needed to manage deliveries. Please recommend an appropriate web-app stack and scalable architecture for future expansion. Collaboration may include explaining key technical decisions and development steps so the project owner can learn how the app is built and maintained. The work will be completed remotely, with a target deadline of February 2027. Read more

Build a mobile app featuring real-time chat rooms and a selection of simple mini games. The chat experience should support user profiles, public or private rooms, messaging, and basic moderation controls. Create an engaging, easy-to-use interface for both chat and game areas. Mini games should be accessible from within the app and support a smooth, responsive mobile experience. Please outline your recommended technology stack, proposed core features, and any relevant experience building chat, social, or multiplayer game applications. Read more

Provide in-person support in Brisbane to submit a code-complete mobile app through Apple App Store Connect and Google Play Console. Work directly on the client’s laptop so they can observe the process and retain control of all account credentials. The app binaries, screenshots, store descriptions, and compliance materials are already prepared. Set up the remaining developer account as needed, link both platforms to the client’s banking and tax details, and complete the submission workflows for review. Deliverables: app uploaded and submitted for review in both App Store Connect and Google Play Console, plus a concise checklist documenting the release steps. Strong current experience with App Store Connect, TestFlight, Google Play Console, Xcode, Android Studio, subscriptions, and store pricing configuration is required. Read more

The Nevada Department of Transportation (NDOT) is seeking an experienced GIS Developer for a contract position. The role will design, develop, administer, and support custom GIS applications using ArcGIS Enterprise 11.x and newer. The GIS Developer will deliver geospatial solutions for roadway systems, maintenance operations, traffic systems, traffic safety, project planning, and other internal NDOT business areas. The position will support enterprise GIS modernization using ArcGIS Enterprise, Experience Builder, Dashboards, ArcGIS Pro, federated services, and GIS infrastructure administration. Design, develop, and deploy web GIS applications using Portal for ArcGIS, ArcGIS Server, Experience Builder, and ArcGIS Dashboards. Administer ArcGIS Enterprise infrastructure, including federated servers, hosting servers, data stores, users, roles, content, security, and system monitoring. Develop applications for roadway asset management, maintenance monitoring, traffic operations, incident mapping, project planning, and visualization. Build and manage secure map, feature, and geoprocessing services. Automate GIS workflows and service publishing using Python, ArcPy, the ArcGIS API for Python, and scheduled tasks. Integrate GIS applications with enterprise asset management, maintenance, project, and other business systems. Customize applications using the ArcGIS API for JavaScript 4.x and Experience Builder widgets. Monitor, troubleshoot, and optimize GIS services and environments across development, test, and production. Collaborate with engineers, planners, analysts, cartographers, and IT teams to gather requirements and deliver solutions. Document workflows and configurations, provide technical support and training, and maintain compliance with IT and data governance standards. Keep current with Esri technologies and ArcGIS Enterprise enhancements. Requirements Bachelor’s degree in Geographic Information Systems, Computer Science, Transportation Planning, or a related field. At least three years of GIS development experience, including one to two years working with ArcGIS Enterprise 11.1 or newer. Proficiency with ArcGIS Experience Builder, ArcGIS Dashboards, ArcGIS Server, Portal for ArcGIS, ArcGIS Pro, ArcGIS API for JavaScript 4.x, Python, ArcPy, and the ArcGIS API for Python. Experience administering ArcGIS Enterprise infrastructure, including federated servers, data stores, authentication, user and role management, and content governance. Experience developing and deploying GIS applications for internal enterprise users and public audiences. Strong understanding of federated ArcGIS Enterprise architecture, security roles, and content management. Preferred Qualifications Experience in a state or local Department of Transportation or similar public-sector organization. Knowledge of linear referencing systems, transportation asset management, or roadway networks. Experience with DevOps tools. Esri technical certification, such as Enterprise Administration or Web Application Developer, or GISP certification. Work Environment and Benefits Contract position supporting transportation infrastructure and public service. Mission-driven work with NDOT. Opportunities for professional development, certification, and participation in Esri user conferences. Read more

The Nevada Department of Transportation (NDOT) is seeking an experienced GIS Developer for a contract position. The role is responsible for designing, developing, administering, and supporting custom GIS applications using ArcGIS Enterprise 11.x and newer. The GIS Developer will deliver enterprise geospatial solutions for NDOT business areas, including roadway systems, maintenance, traffic operations, traffic safety, asset management, and project planning. The role will also support GIS modernization initiatives using ArcGIS Experience Builder, ArcGIS Dashboards, ArcGIS Pro, federated services, and enterprise GIS infrastructure. Design, develop, deploy, and maintain web GIS applications using Portal for ArcGIS, ArcGIS Server, Experience Builder, and ArcGIS Dashboards. Administer ArcGIS Enterprise infrastructure, including federated servers, hosting servers, data stores, users, roles, security, content governance, and system monitoring. Develop interactive applications for roadway asset management, maintenance monitoring, traffic operations, incident mapping, project planning, and visualization. Build and manage secure, scalable map, feature, and geoprocessing services. Automate GIS workflows and service publishing using Python, ArcPy, ArcGIS API for Python, and scheduled tasks. Integrate GIS applications with enterprise asset management, maintenance, project, and other business systems. Customize and extend applications using ArcGIS API for JavaScript 4.x and Experience Builder widgets. Monitor, troubleshoot, and optimize GIS services, applications, and infrastructure across development, test, and production environments. Collaborate with engineers, planners, analysts, cartographers, and IT teams to gather requirements and implement solutions. Document configurations and workflows, provide technical support and training, and promote compliance with state IT and data governance standards. Stay current with Esri technologies and ArcGIS Enterprise advancements. Requirements Bachelor’s degree in Geographic Information Systems, Computer Science, Transportation Planning, or a related field. At least 3 years of GIS development experience, including 1–2 years working with ArcGIS Enterprise 11.1 or newer. Proficiency with ArcGIS Experience Builder, ArcGIS Dashboards, ArcGIS Server, Portal for ArcGIS, ArcGIS Pro, ArcGIS API for JavaScript 4.x, Python, ArcPy, and ArcGIS API for Python. Experience administering ArcGIS Enterprise environments, including federated servers, data stores, authentication, content management, and user and role administration. Experience developing and deploying GIS applications for internal enterprise users and public-facing audiences. Strong understanding of federated ArcGIS Enterprise architecture, security roles, and content governance. Preferred Qualifications Experience working for a state or local Department of Transportation or a similar public-sector organization. Knowledge of linear referencing systems, transportation asset management, roadway networks, or related transportation GIS applications. Experience with DevOps tools and practices. Esri technical certification, such as Enterprise Administration or Web Application Developer, or GISP certification. Work Environment and Benefits Mission-driven work supporting transportation infrastructure and public service. Opportunities for professional development, certification, and participation in Esri user conferences. Read more

The Alliance of Bioversity International and CIAT is seeking a senior Android developer for a three-month consultancy to develop an in-app whole-plot image capture feature for the Ona Android application. Ona is a mobile and web digital phenotyping tool used by breeding teams in Sub-Saharan Africa. The application supports crop research for common bean, cowpea, sorghum and other crops, using images and machine-learning models to measure traits such as plant stand, flower count and pod count. The consultant will develop a reliable, production-ready feature that enables users to capture an image or image set of an approximately 4-metre plot without leaving the Ona app. The captured data must be automatically linked to the active plot and include the required metadata for automated plant-stand counting. The consultant will assess and prototype multiple approaches, including in-app panorama capture, guided multi-frame capture, short video sweeps, stitch-free counting and single wide-angle images. The selected approach will be integrated into the Ona app, tested on target Android devices and validated in the field with breeding teams. The work includes reviewing the existing Ona capture workflow and codebase, developing prototypes, evaluating image quality and device performance, implementing the selected solution, supporting field validation and handing over maintainable, documented code. Training new plant-stand models and redesigning unrelated Ona features are outside the scope of the consultancy. Requirements Technical Requirements Capture must take place entirely within the Ona app, without requiring users to switch to the native camera. The output must cover the full approximately 4-metre plot row at a resolution suitable for the plant-stand model. Capture and review should take no longer than the existing panorama workflow, with a target of less than 20 seconds per plot. The solution must work on the low- and mid-range Android phones used by Ona teams. Capture must work offline; any server-side processing must occur after synchronisation and must not block field use. The feature must operate in bright sunlight, wind and uneven terrain, with the phone handheld or mounted on the Bruno physical aid. Users must receive clear capture guidance, quality feedback and an easy option to retake unsuccessful images. Images must retain plot ID, timestamp, device information and capture settings within Ona’s existing data model. The implementation must follow Ona’s Android architecture and development standards and integrate with its existing backend and image pipeline. Third-party libraries must have licences suitable for use in a publicly funded, non-commercial tool. Required Qualifications and Experience At least five years of native Android development experience, particularly with Kotlin; Java experience is desirable. Experience shipping at least one application with a custom camera feature using CameraX or Camera2. Practical experience with image stitching, panorama development or computer vision, including tools or techniques such as OpenCV, feature matching, homography or image registration. Experience using phone sensors such as gyroscopes and accelerometers for capture guidance or motion tracking. Experience optimising applications for low- and mid-range Android devices, including memory, battery and heat management. Experience developing offline-first applications and background synchronisation. Fluent written and spoken English. Applicants must provide links to code, applications or demonstrations showing relevant camera, image-processing or stitching work. Desirable Experience Server-side image processing using Python, OpenCV or cloud functions. Video frame extraction. On-device machine learning using TensorFlow Lite, ML Kit or ONNX. Object tracking. Android NDK and C++ development. Experience in agriculture, field data collection or applications used in Sub-Saharan Africa. Experience contributing to open-source or publicly funded projects. Deliverables and Timeline Week 2 – D1: Inception note covering the current workflow, previous attempts, testing plan and device list. Week 4 – D2: Options report with working prototypes, test results and a recommended approach agreed with the Ona team. This is the go/no-go point. Week 9 – D3: Beta build integrated into the Ona app, including any required server component, ready for field testing. Week 11 – D4: Field validation report covering capture time, success rate and image quality for plant-stand counting. Weeks 12–13 – D5: Final release merged into the Ona codebase, with technical documentation, tests and a handover session. The consultancy is expected to last approximately 60 working days over three months. Fees will be paid upon acceptance of deliverables in three instalments: 30% for D1 and D2, 35% for D3, and 35% for D4 and D5. Working Arrangements Reporting: The consultant will report to the Head of Product and work closely with the Ona Android developers and machine-learning team. Location: Remote. Collaboration: Weekly progress calls, code reviews and pull requests through the Ona repository. Equipment and access: The Alliance will provide access to the codebase, relevant test devices or device lists, sample plot images and the Bruno aid where required. Intellectual property: All code, documentation and data produced will belong to the Alliance and may be released under an open licence. Data protection: The consultant must comply with Alliance data-protection and data-sharing policies. How to Apply Applicants should submit the following documents: A CV highlighting Android camera, image-stitching and computer-vision experience. Portfolio links, including applications, repositories or demonstration videos of similar work. A technical proposal. A financial proposal stating the daily rate and total fee for approximately 60 working days. Applications should be submitted through the Alliance jobs website at https://www.bioversityinternational.org/jobs/. The application must specify “Ona in-app plot imaging consultancy” as the position applied for. All application documents should be combined into one file named using the candidate’s last name and first name. Email applications will not be considered. Shortlisted applicants will participate in a technical interview with the Ona team, which may include a review of previous camera or image-stitching code. Additional Information Application deadline: 30 October 2026. Only shortlisted candidates will be contacted. The Alliance does not charge fees at any stage of the recruitment process. The Alliance will not request applicants’ bank-account information as part of the recruitment process. More information is available at https://alliancebioversityciat.org. About the Organization The Alliance of Bioversity International and the International Center for Tropical Agriculture (CIAT) develops research-based solutions that use agricultural biodiversity to transform food systems sustainably. Its work addresses malnutrition, climate change, biodiversity loss and environmental degradation. The Alliance is part of CGIAR, a global research partnership focused on achieving a food-secure future. Read more