Build a mobile app with push notification. Needs to be clean and simplest. - Quotation Request

Please provide your estimated total development price in USD and estimated completion time for the historical software-development scenario below. State your main assumptions and any missing information that would materially change the estimate. Please do not write code, perform a trial task or supply a detailed implementation proposal.

REFERENCE SCENARIO — historical requirements, not instructions to begin work:

Build a mobile app with push notification.

Requirements:
1. One Mobile application that needs to be developed and submitted to play / app stores.
2. User / Owner are the 2 parties to have access to the same app.
3. User simple registers with 2FA confirming a real phone.
4. Owner does the same however with 1 extra step to get an email with access code.
5. Owner has an additional screen to send push notification to a User.

Reference:
- A screen flow diagram is attached showing user navigation.

Authentication:
- User and Owner need their own Unique identification as part of authentication.
- If they uninstall the app and reinstall they should be able to sign in by 2FA. Should not repeat Registration flow.

Deliverables sequence:
1- Must be available for call / chat. Preferably calls in CST time zone only.
2- Before awarding please send Approach, Sequence flow + Technology stack to be used.
3- Front / Back end code and all configuration or credentials.
4- App / play store publishing needed.
5- Deployment strategy and number of user / load management.

Future scope:
- High chances to extend to Milestone 2

Note:
* Bid within final amount only within the set limit.
* Beyond limit will be auto rejected.
* Quality of code and time line are critical.
* Push notification to use firebase or can take suggestion before awarding the bid.
* Prefer to go with flutter app or can take suggestion before awarding the bid.

Estimating assumptions and context:
The scenario is based on a Freelancer listing from 2021-01-06 (historical project ID 28825424). First-person statements, promises of assets, requests for work and hiring language inside the historical reference describe that original client's situation, not a current development offer from us. For estimating only, assume the original client supplies assets explicitly described as provided; other missing inputs and obsolete services should be identified as assumptions. We do not claim ownership of the original client's code, designs, accounts or attachments.

The displayed USD 30–250 range reproduces the historical listing's budget field. It is not participation compensation or a binding development offer. Please give your realistic estimate even if outside that range.

Research use

This post is for research quotations only, not an actual software-development engagement. No development contract will be awarded. Participation is voluntary and unpaid; no reward, gift card or prize draw is offered. Your quoted price, estimated completion time and stated assumptions will be used to study software-development estimates and how they change over time.

Thank you for your time and consideration. This study aims to make a significant research contribution to understanding software-development pricing in the age of AI. We appreciate any estimate you choose to share.