Terms of Use

Welcome to Deikon.

These Terms of Use govern your access to and use of Deikon, including our website, web app, mobile app, and related services (together, the "Service").

By using Deikon, you agree to these Terms. If you do not agree, you must not use the Service.

1. Provider

Deikon is provided by:

Philip Dimitris Doukakis ELTA ACHILLEIOY POST BOX 57 49084, CORFU GREECE Email: support@deikon.app

2. What Deikon is

Deikon is a digital tool for creating, managing, comparing, saving, and exporting construction cost estimates, scenarios, reports, and related project information.

Deikon is intended for general informational, calculation-support, and project-organization purposes only. Unless expressly stated otherwise, Deikon does not provide architectural, engineering, legal, tax, accounting, financial, or other professional advice.

3. Eligibility and Acceptable Use

You may use Deikon only in compliance with these Terms and applicable law.

You agree not to:

• use the Service for unlawful, fraudulent, or misleading purposes;
• interfere with, disable, damage, or compromise the Service or its security;
• attempt unauthorized access to accounts, systems, or data;
• reverse engineer, scrape, or misuse the Service, except where such restriction is not permitted by law;
• upload or submit content that you do not have the right to use;
• use the Service in a way that harms Deikon, other users, or third parties.

4. Accounts and Access

Some features require an account.

On the web version of Deikon, account-related features may include email/password sign-up and sign-in, password reset, email confirmation flows, and third-party sign-in options where offered, including Google Sign-In.

If you create or use an account, you must:

Each subscription is personal to the subscribed user and may not be shared with other individuals. To protect account security and prevent misuse, Deikon may limit each subscribed user account to a maximum of two active sign-in sessions at the same time. If this limit is reached, the user may need to sign out from another device or session before continuing.

To help protect accounts and manage access, Deikon may maintain device and session controls, including session expiry, device registration, and session or device revocation.

We may suspend or restrict access where reasonably necessary for security, maintenance, suspected misuse, breach of these Terms, or legal reasons.

• provide accurate and up-to-date information;
• keep your login credentials secure;
• be responsible for activity under your account to the extent you are responsible for it;
• notify us promptly if you suspect unauthorized access to your account.

5. Your Content and Project Data

You retain your rights in the project data, scenarios, estimate inputs, saved reports, and other materials you submit or store in Deikon ("User Content").

You grant us the limited rights necessary to host, store, process, transmit, generate, and display User Content solely for the purpose of operating, securing, maintaining, and providing the Service to you.

You are responsible for ensuring that your User Content:

• is lawful;
• does not infringe third-party rights;
• does not contain malicious code or harmful material.

6. Local and Cloud Storage

Depending on how you use Deikon, your data may be stored locally on your device or browser, or in cloud infrastructure used to provide the Service.

For example:

You are responsible for keeping copies of any information you consider important.

• signed-in web users may have projects and related data stored in Deikon's backend services;
• guest or local-use flows may store certain data in browser storage;
• the mobile app may store certain project, onboarding, export, and app-state data locally on the device.

7. Paid Features, One-Time Purchases, and Subscriptions

Some Deikon features may be paid.

Deikon may offer:

Before you complete a paid purchase or subscription, the relevant price and billing terms should be shown to you.

One-time PDF export purchases, including Breakdown PDF and Comparison PDF exports, apply only to the specific estimate data, scenario selection, and output file generated at the time of purchase. If you change any input field, project value, scenario value, activate or deactivate a scenario, change the selected scenarios, or make any other change that affects the generated PDF output, the previous one-time purchase will not automatically cover the new output. In that case, the paywall may appear again and a new one-time purchase may be required to export the updated PDF. Please review your inputs and selected scenarios carefully before purchasing a one-time PDF export.

Payments may be processed by third-party payment providers or platforms, including Stripe, whose own terms and policies may also apply.

• recurring subscriptions for access to certain features or tiers; and
• one-time purchases, including purchases related to PDF exports or similar digital outputs.

8. Plan Features and Usage Limits

Deikon may offer different plans, tiers, one-time purchases, and feature bundles. Access to specific features may depend on the plan, purchase, platform, or current product offering shown at the time of purchase or inside the Service.

Plan-related differences may include, for example:

The exact features, limits, and prices of each plan or purchase option are the ones presented to you at the time of the relevant offer, checkout, or account/billing interface.

We may update plan names, packaging, feature structure, or eligibility rules from time to time for technical, legal, operational, or commercial reasons. Such changes will not retroactively remove rights already granted for a period already paid for, except where required by law, security, abuse prevention, or platform rules.

• access to specific app features;
• PDF export entitlements or one-time export purchases;
• limits related to saved projects, reports, scenarios, or sync functionality;
• access to subscription-only features or professional features.

9. Subscriptions, Trials, Renewal, Changes, and Cancellation

If Deikon offers subscriptions, the following rules apply unless otherwise stated at the time of purchase or required by applicable law or platform rules.

a. Start of subscription Your subscription starts when payment is successfully completed and the relevant paid access is activated.

b. Auto-renewal Subscriptions renew automatically at the end of each billing period unless cancelled before renewal.

c. Cancellation You may cancel your subscription at any time. Unless otherwise required by law or stated at the time of purchase, cancellation takes effect at the end of the current billing period. After cancellation, paid features generally remain available until the end of that already-paid period and then expire or revert to the applicable lower-access state.

d. Upgrades and downgrades If you change from one paid plan to another, the change is handled through the applicable billing provider, such as Stripe on the web or Google Play on Android, or through Deikon where applicable. Unless Deikon clearly offers and confirms a billing-interval change, the new plan uses your existing billing interval. For example, changing from Plus yearly to Pro changes the subscription to Pro yearly, and changing from Pro monthly to Plus changes it to Plus monthly.

Upgrades may take effect immediately and may result in a prorated charge or price difference for the remaining billing period. Downgrades usually take effect after the current billing period ends, so you keep access to your current plan until then. Any credits, charges, taxes, timing, or other billing adjustments depend on the applicable billing provider, your platform, and the subscription rules shown at the time of change.

e. Free trials and feature trials Deikon may offer free trials and feature trials for paid plans.

If you do not already have an active paid subscription, a trial is handled through the applicable billing provider, such as Stripe on the web or Google Play on Android. When you start a trial, the selected plan and billing interval are used for the subscription that begins after the trial. During this type of trial, you may use the selected plan’s calculation and feature set. Final PDF and Excel exports are not included during the trial and become available only after payment, unless purchased separately as a one-time export.

If you already have an active paid subscription, Deikon may offer a feature trial of a higher plan. This type of trial is handled by Deikon and not directly by Stripe or Google Play. During the feature trial, your existing paid subscription remains active and your existing export access continues. The feature trial uses the billing interval of your existing subscription. Unless you cancel the upgrade after trial before the trial ends, your subscription will automatically upgrade to the trial plan after the trial with the same billing interval. If you cancel the upgrade after trial, you may continue using the trial features until the trial ends, but your subscription remains on your original plan and billing interval after the trial.

Unless explicitly stated otherwise, trials and promotional offers may be limited to one use per user, account, plan, platform, or billing provider. Deikon may change, limit, or withdraw trials or promotional offers where permitted by law.

f. Failed payments If a payment fails, we may suspend, limit, or revoke access to paid features until payment is successfully completed.

g. Billing providers Subscriptions, one-time purchases, cancellations, plan changes, and billing management may be handled through third-party providers or platforms, including Stripe, and may also be subject to their applicable terms, billing logic, and platform rules.

h. No refund rights beyond applicable law or stated policy Except where required by applicable law, platform rules, or an expressly stated refund policy, fees for subscriptions, one-time purchases, and digital outputs are non-refundable once the relevant paid digital service or entitlement has been provided.

i. Current commercial terms The exact current commercial terms presented at checkout, in the pricing interface, or in your billing settings form part of the subscription and purchase framework applicable to your order.

• may be limited to eligible users only;
• may convert into a paid subscription automatically at the end of the trial or promotional period;
• may require cancellation before renewal to avoid being charged.

10. Estimates, Reports, and No Professional Advice

Construction cost estimates, scenario outputs, comparisons, summaries, and reports generated by Deikon depend on user inputs, assumptions, parameters, and product logic.

All results are indicative estimates only. They do not replace professional review, planning, tendering, quotations, accounting review, legal review, or technical advice.

You are responsible for independently reviewing any result before making financial, construction, commercial, contractual, legal, or technical decisions.

11. Availability and Changes

We aim to keep Deikon available and functional, but we do not guarantee uninterrupted, secure, or error-free availability at all times.

We may update, improve, modify, suspend, or discontinue parts of the Service where reasonably necessary, including for technical, security, legal, operational, or product reasons.

12. Intellectual Property

The Service, including its software, design, structure, branding, interface, text, graphics, and related materials, is protected by applicable intellectual property laws.

Except as expressly permitted, you may not copy, sell, license, distribute, modify, or commercially exploit any part of Deikon without prior written permission.

We grant you a limited, non-exclusive, non-transferable, revocable right to use the Service for its intended purposes.

13. Third-Party Services

Deikon may rely on third-party services to provide parts of the Service, including authentication, hosting, payments, customer billing management, or technical delivery features.

Your use of certain third-party-connected functions may also be subject to the terms or policies of those providers.

14. Liability

To the fullest extent permitted by law, Deikon is provided "as is" and "as available".

We do not accept liability for indirect, incidental, special, consequential, or purely economic loss, including loss of profits, business, contracts, expected savings, or data, except where liability cannot be excluded under applicable law.

Nothing in these Terms excludes or limits liability for fraud, willful misconduct, gross negligence where not excludable, or death or personal injury caused by negligence where such liability cannot be excluded by law.

15. Termination

You may stop using Deikon at any time.

We may suspend or terminate access to the Service where reasonably necessary, including for breach of these Terms, security risks, misuse, legal obligations, or discontinuation of the Service.

16. Privacy

Information about how we process personal data, cookies, and device storage is set out in our Privacy Policy.

17. Changes to These Terms

We may update these Terms from time to time.

The current version will be made available through the Service. Where required, we will notify users of material changes in an appropriate manner.

18. Governing Law

These Terms are governed by the laws of Greece, unless mandatory consumer protection law provides otherwise.

If you are a consumer in the European Union, mandatory consumer protection rights in your country of residence remain unaffected.

19. Contact

For questions about these Terms or the Service, contact:

Philip Dimitris Doukakis ELTA ACHILLEIOY POST BOX 57 49084, CORFU GREECE Email: support@deikon.app